[CONCURRENCE SHEET]{.underline}

SAMPLING REQUIREMENTS AND MAXIMUM ALLOWABLE IMPURITIES

FOR SSC FLUIDS AND FLUID SYSTEMS

[Richard J. Gilbrech]{.underline} [04/27/00]{.underline} [Samuel Dale
McCarty]{.underline} [04/27/00]{.underline}

NASA PROPULSION DATE NASA CENTER OPERATIONS DATE

TEST DIRECTORATE DIRECTORATE

[John L. Gasery, Jr.]{.underline} [04/27/00]{.underline} [Issued
CEF]{.underline} [04/28/00]{.underline}

NASA S&MA DATE CENTRAL ENGINEERING FILES DATE

[CHANGE RECORD]{.underline}

  ---------- ------------ ------- ----------------------------------------
  REVISION   DATE         PAGE    DESCRIPTION

  H          26 Apr 00    All     Complete rewrite including title change.
                                  Implements change for waiver NA49 (dated
                                  4/10/92) re: LOX moisture analyses.

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  

                                  
  ---------- ------------ ------- ----------------------------------------

[CONTENTS]{.underline}

[Section]{.underline} [Page]{.underline}

1.0 INTRODUCTION [1](#introduction)

1.1 PURPOSE [1](#purpose)

1.2 SCOPE [1](#scope)

1.3 RESPONSIBILITIES [1](#responsibilities)

1.3.1 SSC Activities [1](#ssc-activities)

1.3.2 Quality Control [1](#quality-control)

2.0 REFERENCED DOCUMENTS [2](#referenced-documents)

3.0 GENERAL REQUIREMENTS [2](#general-requirements)

3.1 SAFETY [2](#safety)

3.2 CONTROLLED ENVIRONMENTS [2](#controlled-environments)

3.3 PROCEDURES [3](#procedures)

3.4 PERSONNEL INSTRUCTION [3](#personnel-instruction)

3.5 SAMPLING [3](#sampling)

3.6 CERTIFICATION RECORDS [3](#certification-records)

3.7 REPORTS [3](#reports)

3.8 ANALYSIS EQUIPMENT [4](#analysis-equipment)

4.0 MAXIMUM ALLOWABLE IMPURITIES [4](#maximum-allowable-impurities)

5.0 FLUID SUPPLY SYSTEM CLEANLINESS REQUIREMENTS
[6](#fluid-supply-system-cleanliness-requirements)

5.1 CERTIFICATION OF FLUID SYSTEMS [6](#certification-of-fluid-systems)

5.1.1 Initial Certification [6](#initial-certification)

5.1.2 Periodic Certification [6](#periodic-certification)

5.1.3 Cylinder Supplied Gas Certification
[7](#cylinder-supplied-gas-certification)

5.1.4 Intermittent Certification of Usage Points
[7](#intermittent-certification-of-usage-points)

5.1.5 Testing, Drying and Preservation
[7](#testing-drying-and-preservation)

5.2 RECERTIFICATION OF SYSTEMS [8](#recertification-of-systems)

5.2.1 Required [8](#required)

5.2.2 Not Required [8](#not-required)

6.0 RECORDS AND FORMS [9](#records-and-forms)

APPENDIX A ACRONYMS AND ABBREVIATIONS [10](#acronyms-and-abbreviations)

APPENDIX B DEFINITIONS [11](#definitions)

[TABLES]{.underline}

[No.]{.underline} [Title]{.underline} [Page]{.underline}

1 PROPELLANTS AND PRESSURANTS MAXIMUM

ALLOWABLE IMPURITIES 4

# 1.0 INTRODUCTION

## 1.1 PURPOSE

This SSC standard (STD) establishes the maximum allowable impurities and
sampling criteria for the fluids (gases, liquids) used as propellants
and pressurants to clean, test, dry, or preserve test systems,
subsystems, assemblies, components, and support equipment at Stennis
Space Center (SSC).

## 1.2 SCOPE

This STD applies to site-wide facility systems (including offsite
procurements) associated with the following services.

-   High Pressure (Missile Grade) Air (HPA)

-   Helium (He)

-   Hydrogen, Gas (GH~2~) and Liquid (LH~2~)

-   Nitrogen, Gas (GN~2~) and Liquid (LN~2~)

-   Oxygen, Gas (GOX) and Liquid (LOX)

## 1.3 RESPONSIBILITIES

### 

### 1.3.1 SSC Activities

This standard shall be implemented by NASA and Contractor personnel
responsible for engineering design, manufacture, fabrication, analysis,
inspection, or test operations. NASA and the Contractor shall ensure
compliance with the requirements of this standard through surveillance,
auditing, and process verification. The SSC Propulsion Test Directorate
(PTD) Test Engineering Division and the Center Operations and Support
Directorate Facilities Engineering Division (FED) are responsible for
the content of this SSC STD. Revision or cancellation of this STD shall
be reviewed and approved as specified in SLP-05 and SSC STD 99-008.

### 1.3.2 Quality Control

NASA and/or Contractor QA are responsible for verifying the
certification of systems. The scheduling and the frequency of sampling
shall be as indicated in Section 5.0.

# 2.0 REFERENCED DOCUMENTS

The referenced documents form an integral part of this standard and the
latest issues shall apply unless otherwise specified.

FED-STD 209 Airborne Particulate Cleanliness Classes in Clean Rooms and
Clean Zones

MIL-PRF-25508 Performance Specification, Propellant, Oxygen (Grade A)

MIL-PRF-27201 Performance Specification, Propellant, Hydrogen

MIL-PRF-27401 Performance Specification, Propellant Pressurizing Agent,
Nitrogen (Grade B)

MIL-PRF-27407 Performance Specification, Propellant Pressurizing Agent,
Helium (Grade A)

SLP-05 Document and Data Control

SLP-16 Control of Quality Records

SPG 8715.1 NASA/SSC Safety and Health Procedures and Guidelines

SSC STD 79-001 Surface Cleanliness Requirements for SSC Facility Fluid
Systems

SSC STD 99-008 Guide for the Preparation, Approval and Release of SSC
Standards

# GENERAL REQUIREMENTS

## 3.1 SAFETY

All procedures in this standard shall be performed in accordance with
applicable requirements in SPG 8715.1.

## 3.2 CONTROLLED ENVIRONMENTS

Areas where particulate samples are analyzed shall conform to
requirements for controlled environment areas per FED-STD-209.

## 3.3 PROCEDURES

The performing unit shall work to approved procedures for performing all
sampling and analyses. The NASA Monitor/Project Engineer and the NASA
Quality Assurance Representative responsible for system integrity shall
approve these procedures prior to work.

## 3.4 PERSONNEL INSTRUCTION

Personnel involved in obtaining and analyzing test samples shall be
trained and/or certified and shall wear proper personal protective
equipment (PPE). Precautions must be taken to prevent introduction of
contaminants into test samples.

## 3.5 SAMPLING

Samples shall be taken at the gas user interface point downstream of
filters, regulators, valves, and any other equipment normally installed
in a line. If maintenance is performed without contamination control
(79-001), or when contamination is suspected, then additional samples
shall be taken at the next downstream user interface point. Unless
otherwise specified, gas sample volume shall be a minimum of 0.850
standard cubic meter.

## 3.6 CERTIFICATION RECORDS

Logs or databases shall be used to document all sampling at each use
point in order to monitor trends and/or failures. The data from these
logs or databases will be maintained by the performing organization and
may be used to determine if the sampling frequency as required by
Section 5.1.2 needs to be modified.

## 3.7 REPORTS

All data gathered as a result of this standard shall be documented by
the performing organization as designated by NASA QA, and shall include
pertinent information recorded in logs or databases per section 3.6.

## 3.8 ANALYSIS EQUIPMENT

The equipment used to perform the analyses specified herein shall be
approved for contamination testing by the performing organization as
designated by NASA QA.

**[CAUTION]{.underline}**

**Prior to use, hand tools, materials, and equipment that may come into
contact with significant surfaces or the service media shall be
certified cleaned to the required system or component clean level in
accordance with SSC STD 79-001.**

# 4.0 MAXIMUM ALLOWABLE IMPURITIES

Requirements for maximum allowable impurities in the SSC Facility
Transfer Systems at the receiving and user interface points are
specified in Table 1. (Note that service fluid purity levels differ from
system and component clean levels specified by SSC STD 79-001.)

###### NOTE 

> The impurities in all fluid samples shall be analyzed in the gaseous
> state.

TABLE 1. PROPELLANTS AND PRESSURANTS MAXIMUM ALLOWABLE IMPURITIES

+-----------------------+-----------------------+----------------------+
| PROPELLANT/PRESSURANT | REQUIREMENTS\*        |                      |
+=======================+=======================+======================+
| PARAMETER             | RECEIVING             | USER INTERFACe       |
|                       |                       | POINTS               |
+-----------------------+-----------------------+----------------------+
| HELIUM, GAS (He) Ref  |                       |                      |
| MIL-PRF-27407 (Grade  |                       |                      |
| A)                    |                       |                      |
+-----------------------+-----------------------+----------------------+
| Purity                | 99.995% He (min.)     | 99.994% He (min.)    |
|                       |                       |                      |
| Total Impurities      | 50                    | N/A                  |
|                       |                       |                      |
| Specific Impurities   | N/A                   | 60                   |
|                       |                       |                      |
| H~2~                  | 1                     | N/A                  |
|                       |                       |                      |
| N~2~ and Argon        | 14                    | 36                   |
| (receiving only)      |                       |                      |
|                       | 3                     | 10                   |
| O~2~ and Argon (UIP   |                       |                      |
| only)                 | 9 (-61.1C Dew Point)  | 9 (-61.1C Dew Point) |
|                       |                       |                      |
| H~2~O                 | 5                     | 5                    |
|                       |                       |                      |
| Hydrocarbon\*\*       | 23                    | N/A                  |
|                       |                       |                      |
| Neon                  | 1                     | N/A                  |
|                       |                       |                      |
| CO                    | 1                     | N/A                  |
|                       |                       |                      |
| CO~2~                 | N/A                   | 30-100: 25; \>100: 0 |
|                       |                       |                      |
| Particulate (gas)     | N/A                   | N/A                  |
|                       |                       |                      |
| Particulate (liquid)  |                       |                      |
+-----------------------+-----------------------+----------------------+

TABLE 1. (Continued)

+----------------------+---+----------------------+---+----------------------+
| P                    |   | REQUIREMENTS\*       |   |                      |
| ROPELLANT/PRESSURANT |   |                      |   |                      |
+======================+===+======================+===+======================+
| PARAMETER            |   | RECEIVING            |   | USER INTERFACe       |
|                      |   |                      |   | POINTS               |
+----------------------+---+----------------------+---+----------------------+
| HYDROGEN, GAS OR     |   |                      |   |                      |
| LIQUID (H~2~) Ref    |   |                      |   |                      |
| MIL-PRF-27201        |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| Purity               |   | 99.995% H~2~ (min.)  |   | 99.993% H~2~ (min.)  |
|                      |   |                      |   |                      |
| Total Impurities     |   | 50                   |   | N/A                  |
|                      |   |                      |   |                      |
| Specific Impurities  |   | N/A                  |   | 70                   |
|                      |   |                      |   |                      |
| Selected Impurities: |   | 95.0% (liquid H~2~   |   | N/A                  |
|                      |   | only)                |   |                      |
| Parahydrogen         |   |                      |   | 20 (9 for H~2~O)     |
|                      |   | 9 (-61.1C Dew Point) |   |                      |
| N~2~, H~2~O,         |   |                      |   | (-61.1C Dew Point)   |
| Hydrocarbon\*\*      |   | 1                    |   |                      |
|                      |   |                      |   | 5                    |
| O~2~ and Argon       |   | 39                   |   |                      |
|                      |   |                      |   | 45                   |
| He                   |   | 1                    |   |                      |
|                      |   |                      |   | N/A                  |
| CO~2~ plus CO        |   | N/A                  |   |                      |
|                      |   |                      |   | N/A                  |
| Particulate (gas)    |   | N/A                  |   |                      |
|                      |   |                      |   | N/A                  |
| Particulate (liquid) |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| NITROGEN, GAS OR     |   |                      |   |                      |
| LIQUID (N~2~) Ref    |   |                      |   |                      |
| MIL-PRF-27401 (Grade |   |                      |   |                      |
| B)                   |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| Purity               |   | 99.99% N~2~ (min.)   |   | 99.989% N~2~ (min.)  |
|                      |   |                      |   |                      |
| Total Impurities     |   | 100                  |   | N/A                  |
|                      |   |                      |   |                      |
| Specific Impurities  |   | N/A                  |   | 111                  |
|                      |   |                      |   |                      |
| Selected Impurities: |   | 50                   |   | 100                  |
| O~2~                 |   |                      |   |                      |
|                      |   | 5                    |   | 5                    |
| Hydrocarbon\*\*      |   |                      |   |                      |
|                      |   | 6\*\*\* (-64.0C Dew  |   | 6.0\*\*\*(-64.0C Dew |
| H~2~O                |   | Point)               |   | Point)               |
|                      |   |                      |   |                      |
| Particulate (gas)    |   | N/A                  |   | 30-100: 25; \>100: 0 |
|                      |   |                      |   |                      |
| Particulate (liquid) |   | 1 mg/liter           |   | N/A                  |
+----------------------+---+----------------------+---+----------------------+
| OXYGEN, GAS (GOX) OR |   |                      |   |                      |
| LIQUID (LOX) Ref     |   |                      |   |                      |
| MIL-PRF-25508 (Grade |   |                      |   |                      |
| A)                   |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| Purity               | 9 |                      | 9 |                      |
|                      | 9 |                      | 9 |                      |
| Total Impurities     | . |                      | . |                      |
|                      | 6 |                      | 6 |                      |
| H~2~O                | % |                      | % |                      |
|                      | O |                      | O |                      |
| Hydrocarbon\*\*      | ~ |                      | ~ |                      |
|                      | 2 |                      | 2 |                      |
| (C~2~H~2~) Acetylene | ~ |                      | ~ |                      |
|                      | ( |                      | ( |                      |
| Particulate (gas)    | m |                      | m |                      |
|                      | i |                      | i |                      |
| Particulate (liquid) | n |                      | n |                      |
|                      | . |                      | . |                      |
|                      | ) |                      | ) |                      |
|                      |   |                      |   |                      |
|                      | 4 |                      | N |                      |
|                      | 0 |                      | / |                      |
|                      | 0 |                      | A |                      |
|                      | 0 |                      |   |                      |
|                      |   |                      | 2 |                      |
|                      | 3 |                      | 0 |                      |
|                      | ( |                      | ( |                      |
|                      | - |                      | - |                      |
|                      | 6 |                      | 5 |                      |
|                      | 9 |                      | 5 |                      |
|                      | . |                      | . |                      |
|                      | 0 |                      | 2 |                      |
|                      | C |                      | C |                      |
|                      | D |                      | D |                      |
|                      | e |                      | e |                      |
|                      | w |                      | w |                      |
|                      | P |                      | P |                      |
|                      | o |                      | o |                      |
|                      | i |                      | i |                      |
|                      | n |                      | n |                      |
|                      | t |                      | t |                      |
|                      | ) |                      | ) |                      |
|                      |   |                      |   |                      |
|                      | 5 |                      | 5 |                      |
|                      | 0 |                      | 0 |                      |
|                      |   |                      |   |                      |
|                      | 0 |                      | N |                      |
|                      | . |                      | / |                      |
|                      | 2 |                      | A |                      |
|                      | 5 |                      |   |                      |
|                      | p |                      | 3 |                      |
|                      | p |                      | 0 |                      |
|                      | m |                      | - |                      |
|                      | b |                      | 1 |                      |
|                      | y |                      | 0 |                      |
|                      | w |                      | 0 |                      |
|                      | e |                      | : |                      |
|                      | i |                      | 2 |                      |
|                      | g |                      | 5 |                      |
|                      | h |                      | ; |                      |
|                      | t |                      | \ |                      |
|                      |   |                      | > |                      |
|                      | N |                      | 1 |                      |
|                      | / |                      | 0 |                      |
|                      | A |                      | 0 |                      |
|                      |   |                      | : |                      |
|                      | 1 |                      | 0 |                      |
|                      | m |                      |   |                      |
|                      | g |                      | N |                      |
|                      | / |                      | / |                      |
|                      | l |                      | A |                      |
|                      | i |                      |   |                      |
|                      | t |                      |   |                      |
|                      | e |                      |   |                      |
|                      | r |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| HIGH PRESSURE AIR    |   |                      |   |                      |
| (HPA)                |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+
| Purity               | N |                      | 1 |                      |
|                      | / |                      | 8 |                      |
| H~2~O                | A |                      | % |                      |
|                      |   |                      | O |                      |
| Hydrocarbon\*\*      | N |                      | ~ |                      |
|                      | / |                      | 2 |                      |
| Particulate (gas)    | A |                      | ~ |                      |
|                      |   |                      | ( |                      |
| Particulate (liquid) | N |                      | m |                      |
|                      | / |                      | i |                      |
|                      | A |                      | n |                      |
|                      |   |                      | . |                      |
|                      | N |                      | ) |                      |
|                      | / |                      |   |                      |
|                      | A |                      | 2 |                      |
|                      |   |                      | 4 |                      |
|                      | N |                      | ( |                      |
|                      | / |                      | - |                      |
|                      | A |                      | 5 |                      |
|                      |   |                      | 3 |                      |
|                      |   |                      | . |                      |
|                      |   |                      | 9 |                      |
|                      |   |                      | C |                      |
|                      |   |                      | D |                      |
|                      |   |                      | e |                      |
|                      |   |                      | w |                      |
|                      |   |                      | P |                      |
|                      |   |                      | o |                      |
|                      |   |                      | i |                      |
|                      |   |                      | n |                      |
|                      |   |                      | t |                      |
|                      |   |                      | ) |                      |
|                      |   |                      |   |                      |
|                      |   |                      | 1 |                      |
|                      |   |                      | 5 |                      |
|                      |   |                      |   |                      |
|                      |   |                      | 3 |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      | - |                      |
|                      |   |                      | 1 |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      | : |                      |
|                      |   |                      | 2 |                      |
|                      |   |                      | 5 |                      |
|                      |   |                      | ; |                      |
|                      |   |                      | \ |                      |
|                      |   |                      | > |                      |
|                      |   |                      | 1 |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      | : |                      |
|                      |   |                      | 0 |                      |
|                      |   |                      |   |                      |
|                      |   |                      | N |                      |
|                      |   |                      | / |                      |
|                      |   |                      | A |                      |
+----------------------+---+----------------------+---+----------------------+
| \*Unless otherwise   |   |                      |   |                      |
| specified,           |   |                      |   |                      |
| requirement levels   |   |                      |   |                      |
| are total ppm by     |   |                      |   |                      |
| volume.              |   |                      |   |                      |
|                      |   |                      |   |                      |
| \*\*Total            |   |                      |   |                      |
| hydrocarbons         |   |                      |   |                      |
| expressed as Methane |   |                      |   |                      |
| (CH~4~).             |   |                      |   |                      |
|                      |   |                      |   |                      |
| \*\*\*The maximum    |   |                      |   |                      |
| H~2~O content is 6   |   |                      |   |                      |
| ppm verified from    |   |                      |   |                      |
| the delivery         |   |                      |   |                      |
| manifest. This is    |   |                      |   |                      |
| less than the 11.5   |   |                      |   |                      |
| ppm allowed in       |   |                      |   |                      |
| MIL-PRF-27401;       |   |                      |   |                      |
| however, historical  |   |                      |   |                      |
| data documents       |   |                      |   |                      |
| receipt of product   |   |                      |   |                      |
| within the lower     |   |                      |   |                      |
| limit.               |   |                      |   |                      |
+----------------------+---+----------------------+---+----------------------+

# 5.0 FLUID SUPPLY SYSTEM CLEANLINESS REQUIREMENTS

[NOTE]{.underline}

> Taking gas and/or liquid samples certifies systems, but the impurities
> in all fluid samples are analyzed in a gaseous state.

## 5.1 CERTIFICATION OF FLUID SYSTEMS

Certification of a fluid system shall require testing of the sample
fluid as described in sections 5.1.1, 5.1.2 and 5.1.3.

### 5.1.1 Initial Certification

For certification of a new system, except cylinder supplied gas as
defined in 5.1.3, the following requirements must be satisfied.

a.  Two consecutive samples at each user interface point in the system,
    taken 8 to 72 hours apart, shall comply with the user interface
    point requirements in Table 1.

b.  Two additional samples taken consecutively at 5-to-10-day intervals
    from each user interface point shall comply with the hydrocarbon,
    moisture and particulate user interface point requirements in Table
    1.

### 5.1.2 Periodic Certification

After initial certification of a fluid system, periodic certifications
are required as follows.

[NOTE]{.underline}

> When contamination is suspected, tests shall be performed to verify
> the impurity levels of the fluid. If these tests indicate that
> contamination levels exceed the requirements of 5.1.2-a or -b, then
> necessary corrective action shall be taken to clean and purge the
> system. If three consecutive samples fail, the system shall be
> certified as specified in 5.1.1.

a.  A supply fluid sample taken at the storage vessel, at 6‑month
    intervals, shall comply with the user interface point requirements
    in Table 1.

b.  A sample taken at each user interface point at 3-month intervals
    shall comply with the hydrocarbon, moisture and particulate user
    interface point requirements in Table 1.

### 5.1.3 Cylinder Supplied Gas Certification

A gas system may consist of a cylinder, or a bank of cylinders, equipped
with one or more user interface points.

a.  Initial certification shall require a sample obtained from the user
    interface point downstream from the cylinder gas system. This sample
    must meet the contamination level user interface point requirements
    specified in Table 1. The certification sample shall be taken with
    all bottle valves in the open position.

b.  Periodic certification is not required; however, following cylinder
    replacement or maintenance the provisions of Section 5.2 shall
    apply.

### 5.1.4 Intermittent Certification of Usage Points

User interface points shall be initially certified in accordance with
5.1.1, and periodically certified in accordance with 5.1.2. If an
initially certified user interface point has not subsequently been
periodically certified, then (a) a sample shall comply with the user
interface requirements in Table 1; and (b) a second sample, taken 8 to
72 hours later, shall comply with the hydrocarbon, particulate and
moisture user interface point requirements in Table 1.

### 5.1.5 Testing, Drying and Preservation

Gases used in the testing, drying and preservation of components,
assemblies and support/test equipment shall meet the hydrocarbon,
moisture and particulate user interface point requirements specified in
Table 1. When used for testing, drying and preservation, gas user
interface points that are used daily shall be tested weekly; if used
intermittently, they shall be verified at the time of use.

## 5.2 RECERTIFICATION OF SYSTEMS

### 5.2.1 Required

A fluid system requires recertification when any part has been
disassembled, recleaned, or modified. Recertification requires the
following.

a.  If a positive pressure flow is not maintained, then a sample shall
    be obtained from the next downstream user interface point and tested
    to verify that all parameters comply with the user interface point
    requirements in Table 1. If this test fails, then necessary
    corrective action shall be taken to clean and purge the system. If
    three consecutive samples fail, the system shall be certified as
    specified in 5.1.1.

b.  If a positive flow is maintained, the media shall be tested to
    verify that hydrocarbon, moisture and particulate meet the user
    interface point requirements in Table 1. If this test fails, then
    necessary corrective action shall be taken to clean and purge the
    system. If three consecutive samples fail, the system shall be
    certified as specified in 5.1.1.

### 5.2.2 Not Required

Recertification of a system is not required if all of the following are
verified.

a.  A positive purge is maintained on the system when the system is
    disassembled.

b.  The system is disassembled for removal of a component or instrument
    for recertification or recalibration.

c.  The instrument or component is installed in an open loop
    configuration.

# 6.0 RECORDS AND FORMS

Records and forms identified in this standard shall be maintained in
accordance with SLP-16. For Quality Records refer to the SSC Master
Records Index. All forms are assumed to be the latest edition unless
otherwise specified and may be obtained from the SSC Electronic Forms
repository or from the NASA SSC Forms Management Officer.

# APPENDIX A

# ACRONYMS AND ABBREVIATIONS

C~2~H~2~ Acetylene

CO Carbon Monoxide

CO~2~ Carbon Dioxide

FED Federal

H~2~ Hydrogen

H~2~O Water

He Helium

LH Liquid Hydrogen

LN Liquid Nitrogen

LOX Liquid Oxygen

IPA Isopropyl Alcohol

MIL Military

N~2~ Nitrogen

NASA National Aeronautics and Space Administration

NVR Nonvolatile Residue

O~2~ Oxygen

PRF Performance (spec)

PPE Personal Protective Equipment

ppm Parts per million (p/m)

QA Quality Assurance

SLP System Level Procedure

Spec Specification

SPG SSC Procedures and Guidelines

SSC Stennis Space Center

STD Standard

UIP User Interface Point

# APPENDIX B

# DEFINITIONS

**Certification -** The attesting (in writing) that requirements are
verified as having been met.

**Dew Point** - The temperature at which a gas becomes saturated with
water vapor and condensation begins (usually atmospheric pressure.)

**Fluid** -- Any gas or liquid used to clean, test, dry, or preserve
test systems, subsystems, assemblies, components, and support equipment.

**Hydrocarbon** - Any compound containing carbon and hydrogen bonds.

**Interface Point** -- A specific location where systems intersect.

**Micron** - Dimension of length equal to 0.001 millimeter (0.0000394
inch).

**Moisture** - The residual liquid/gas resulting from cleaned components
or systems, measured in parts-per-million (PPM).

**Nonvolatile Residue (NVR)** - The residue remaining after filtration
and controlled evaporation of the final flushing solvent. NVR is
specified in milligrams (mg) per square meter or square foot of
significant surface. The predominant constituents of NVR are
hydrocarbons.

**Particulate** - Fibers or units of matter with observable length,
width, and thickness, usually measured in microns.

**Significant Surfaces** - Those surfaces of components, piece-parts,
assemblies, subsystems, systems, and ground support equipment that come
in contact with test solvents.

**Standard Cubic Meter** - Volume of one cubic meter of gas at one
atmosphere of pressure (i.e., 760 mm of mercury) at 70ºF (21.1ºC).

**APPENDIX B (continued)**

**DEFINITIONS**

**Testing** - The process of acquiring and analyzing samples to
determine the impurities and purity levels.

**User Interface Point** -- Any specific service port where commodities
are extracted from the system. In some cases, the user interface point
may be the specific port where commodities are injected into the system.

**Verification -** The process whereby one or more of the following
methods is used for the purpose of certification: performing visual
inspection, obtaining samples, analyzing/testing samples and reviewing
inspection/test data.