Pressurized Systems and Cryogens

**Performance Objective:**

Assure personnel health and safety through regularly scheduled
inspections and maintenance on pressure vessels and equipment,
compressed gases and gas cylinders, vacuum equipment and systems,
hydraulics, and cryogenic materials and systems.

**Performance Criteria:**

1.  BN inspects, operates and safely stores unmodified compressed-gas or
    liquid cylinders approved by the Department of Transportation (DOT)
    and the appropriate regulators.

```{=html}
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1.  BN inspects, operates and maintains refrigeration systems that
    comply with the American Society of Mechanical Engineers (ASME)
    Boiler and Pressure Vessel Codes, and applicable Air Conditioning
    and Refrigeration Institute (ARI) standards.

2.  BN inspects, operates and maintains pressure systems that operate at
    an MAWP that is less than one atmospheric pressure. (Design guidance
    for these systems is given in the ASME Unified Pressure Vessel Code
    and the [Mechanical Engineering Design Safety
    Standards](http://www.llnl.gov/es_and_h/dss.html) M-012, Section
    3.3, \"Vacuum Systems.\") However, the requirements do apply to
    vacuum systems that may be pressurized (i.e., for purging, or
    back-filling).

3.  BN inspects, operates and maintains ASME coded air-pressure tanks,
    liquefied petroleum gas tanks, anhydrous-ammonia tanks, and fired
    steam boilers that periodically in accordance with Unfired Pressure
    Vessel Safety Orders or Boiler and Fired Pressure Vessel Safety
    Orders.

4.  BN ensures the safety of personnel through a definitive training
    program on pressurized systems.

## REFERENCES:

[29 CFR 1910.101](http://www.osha-slc.gov/OshStd_data/1910_0101.html),
Compressed Gases General Requirements.

[29 CFR 1910.132, Subpart
I](http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc_1910_SUBPART_I.html),
Personal Protective Equipment.

[29 CFR 1910.146](http://www.osha-slc.gov/OshStd_data/1910_0146.html),
Permit Required Confined Spaces.

[29 CFR 1910, Subpart
J](http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc_1910_SUBPART_J.html),
General Environmental Controls.

[29 CFR 1910, Subpart
M](http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc_1910_SUBPART_M.html),
Compressed Gas and Compressed Air Equipment.

[AGA Z
21.13](http://www.llnl.gov/es_and_h/sourcematerial/sources/library.html),
Gas Fired Low Pressure Steam and Hot Water Boilers (American Gas
Association, 1991).

[ANSI/B
31.1](http://www.llnl.gov/es_and_h/sourcematerial/sources/library.html),
Power Piping, ASME Code for Pressure Piping, 1995.

[ASME Boiler & Pressure Vessel
Codes](http://www.llnl.gov/es_and_h/sourcematerial/sources/pe_library.html),
Section I, \"Boilers,\" 1998.

[ASME Boiler & Pressure Vessel
Codes](http://www.llnl.gov/es_and_h/sourcematerial/sources/pe_library.html),
Section VIII, \"Div. 1 & 2 Rules for Construction of Pressure Vessels,\"
1998.

[Compressed Gas Association (CGA) Pamphlet
P-1](http://www.llnl.gov/es_and_h/sourcematerial/sources/library.html),
Safe Handling of Compressed Gases in Containers, 1995.

[Compressed Gas Association (CGA), Pamphlet
P-12](http://www.llnl.gov/es_and_h/sourcematerial/sources/library.html),
Safe Handling of Cryogenic Liquids, 1993.

[Compressed Gas Association (CGA) Pamphlet
S-1.1](http://www.llnl.gov/es_and_h/sourcematerial/sources/library.html),
Pressure Relief Device Standards, Part 1 Cylinders for Compressed Gases,
1991.

[DOE M
440.1-1](http://www.directives.doe.gov/pdfs/doe/doetext/neword/440/m4401-1.pdf),
DOE Explosives Safety Manual.

DOE Order 440.1A, Attachment 2, Section 20, Pressure Safety

BN Procedure, CD-2110.002, Standard Pressure Systems, 12/7/00

BN Procedure, CD-2110.003, Nonstandard Pressure Systems, 10/30/01

BN Procedure, OP-2110.116, Standard Pressure Safety Inspection, 1/21/03

BN Procedure, OP-2110.131, Pressure testing of Piping, Tubing, and
Components, 2/24/03

**APPROACH:**

**Document Review**:

-   Selected maintenance work packages

-   Selected test documents and/or experiment plans,

-   Selected occurrence report

-   Selected training plans that has been approved and released to the
    field for work.

-   Selected Hot Work Permits

**Observations:**

-   Selected work, testing, or training being performed including crew
    briefings, testing setup and/or conduct of testing, maintenance
    activities, trouble-shooting activities, research and development
    activities, or training activities (classroom or on-the-job).

**Interviews:**

-   Selected Management personnel

-   Selected maintenance, support and/or operations staff

-   Selected Trainers/Training Coordinators

**Pressurized Systems and Cryogens Assessment Plan**

**NNSA/NV Facility Representative**

**Guide for planning the review approach**

+-----+----------------------------+-----+-----+-----+---------------+
| No. | Description                | YES | NO  | N/A | COMMENTS      |
+-----+----------------------------+-----+-----+-----+---------------+
| H   |                            |     |     |     |               |
| igh |                            |     |     |     |               |
| Pr  |                            |     |     |     |               |
| ess |                            |     |     |     |               |
| ure |                            |     |     |     |               |
| Boi |                            |     |     |     |               |
| ler |                            |     |     |     |               |
| O   |                            |     |     |     |               |
| per |                            |     |     |     |               |
| ati |                            |     |     |     |               |
| ons |                            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1\. | Are operations being       |     |     |     |               |
|     | performed on a boiler/air  |     |     |     |               |
|     | tank which is not          |     |     |     |               |
|     | constructed the American   |     |     |     |               |
|     | Society of Mechanical      |     |     |     |               |
|     | Engineers (A.S.M.E) Code?  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2\. | Are all boilers equipped   |     |     |     |               |
|     | with a safety valve,       |     |     |     |               |
|     | having sufficient relief   |     |     |     |               |
|     | capacity, and set at or    |     |     |     |               |
|     | below the maximum          |     |     |     |               |
|     | allowable working          |     |     |     |               |
|     | pressure?                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3\. | Do personnel bypass the    |     |     |     |               |
|     | pressure controls, low     |     |     |     |               |
|     | water cutout, or any other |     |     |     |               |
|     | limit switch or control?   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4\. | Do personnel restrict the  |     |     |     |               |
|     | design function of safety  |     |     |     |               |
|     | valves; i.e., such as      |     |     |     |               |
|     | reducing or plugging the   |     |     |     |               |
|     | outlet, painting, or       |     |     |     |               |
|     | removing it?               |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 5\. | Are unqualified personnel  |     |     |     |               |
|     | permitted to operate a     |     |     |     |               |
|     | boiler?.                   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 6\. | Are operating boilers left |     |     |     |               |
|     | unattended for long        |     |     |     |               |
|     | periods of time?           |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 7\. | Are boilers allowed to     |     |     |     |               |
|     | operate without an         |     |     |     |               |
|     | adequate source of         |     |     |     |               |
|     | combustion air?            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 8\. | Are boilers operating      |     |     |     |               |
|     | without a valid            |     |     |     |               |
|     | certificate of inspection? |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 9\. | Have all boilers been      |     |     |     |               |
|     | internally inspected       |     |     |     |               |
|     | annually, and do they have |     |     |     |               |
|     | an inspection card as      |     |     |     |               |
|     | required by State law?     |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Have all newly installed   |     |     |     |               |
| 0\. | boilers been reported to   |     |     |     |               |
|     | the State Office of Boiler |     |     |     |               |
|     | and Pressure Vessel        |     |     |     |               |
|     | Safety?                    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are safety controls and    |     |     |     |               |
| 1\. | devices tested on a        |     |     |     |               |
|     | periodic basis (as         |     |     |     |               |
|     | recommended by CSD1)?      |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are boiler operators       |     |     |     |               |
| 2\. | adequately trained to      |     |     |     |               |
|     | assure safe and efficient  |     |     |     |               |
|     | operation?                 |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are boilers inspected      |     |     |     |               |
| 3\. | daily for adverse          |     |     |     |               |
|     | conditions prior to proper |     |     |     |               |
|     | operations?                |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Is a log of incidents      |     |     |     |               |
| 4\. | maintained that record     |     |     |     |               |
|     | boiler operations, and     |     |     |     |               |
|     | when safety controls and   |     |     |     |               |
|     | devices were tested (i.e., |     |     |     |               |
|     | low water cutout, safety   |     |     |     |               |
|     | valve(s), combustion       |     |     |     |               |
|     | controller)?               |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are only authorized ("R"   |     |     |     |               |
| 5\. | stamp or proper ASME       |     |     |     |               |
|     | symbol holder) repair      |     |     |     |               |
|     | firms allowed to make      |     |     |     |               |
|     | welded repairs?            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Have burners been          |     |     |     |               |
| 6\. | immediately serviced, if   |     |     |     |               |
|     | the burner starts with a   |     |     |     |               |
|     | puff or operates in an     |     |     |     |               |
|     | unusual manner?            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| C   |                            |     |     |     |               |
| omp |                            |     |     |     |               |
| res |                            |     |     |     |               |
| sed |                            |     |     |     |               |
| Air |                            |     |     |     |               |
| S   |                            |     |     |     |               |
| tor |                            |     |     |     |               |
| age |                            |     |     |     |               |
| T   |                            |     |     |     |               |
| ank |                            |     |     |     |               |
| O   |                            |     |     |     |               |
| per |                            |     |     |     |               |
| ati |                            |     |     |     |               |
| ons |                            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are vessels rigidly        |     |     |     |               |
| 7\. | mounted without vibration  |     |     |     |               |
|     | buffer supports under tank |     |     |     |               |
|     | legs?                      |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are vessels operated       |     |     |     |               |
| 8\. | without a properly         |     |     |     |               |
|     | equipped and calibrated    |     |     |     |               |
|     | pressure gauge?            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 1   | Are pressure control       |     |     |     |               |
| 9\. | switches, or similar       |     |     |     |               |
|     | devices controlling        |     |     |     |               |
|     | pressure, ever bypassed?   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Do personnel restrict the  |     |     |     |               |
| 0\. | design function of any     |     |     |     |               |
|     | safety relief valve: i.e., |     |     |     |               |
|     | tie down, paint, block,    |     |     |     |               |
|     | cap, or remove such valve? |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Are welded repairs         |     |     |     |               |
| 1\. | performed on air tanks?    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Is plastic pipe used on    |     |     |     |               |
| 2\. | any air discharge line?    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Has stock been piled up    |     |     |     |               |
| 3\. | against the tank?          |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Is the safety relief valve |     |     |     |               |
| 4\. | tested monthly?            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Is the condensate drained  |     |     |     |               |
| 5\. | from the tank regularly,   |     |     |     |               |
|     | or daily, if necessary?    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Are the vessels mounted in |     |     |     |               |
| 6\. | level positions at all     |     |     |     |               |
|     | times, with vibration      |     |     |     |               |
|     | protection in place?       |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Have the vessel been       |     |     |     |               |
| 7\. | inspected biannually, as   |     |     |     |               |
|     | required by State law?     |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Are the tanks protected    |     |     |     |               |
| 8\. | from damage caused by      |     |     |     |               |
|     | vehicle traffic or plant   |     |     |     |               |
|     | operations?                |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 2   | Are the vessels inspected  |     |     |     |               |
| 9\. | for air leaks at least     |     |     |     |               |
|     | weekly?  On finding an air |     |     |     |               |
|     | leak, determine its source |     |     |     |               |
|     | (i.e. line, fitting or     |     |     |     |               |
|     | crack).                    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Report new installations |     |     |     |               |
| ~30 | to the State Office of     |     |     |     |               |
| .~~ | Boiler and Pressure Vessel |     |     |     |               |
|     | Safety.~~                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Have all welded repairs  |     |     |     |               |
| ~31 | made only by companies     |     |     |     |               |
| .~~ | holding the "R" stamp      |     |     |     |               |
|     | authorization or the       |     |     |     |               |
|     | A.S.M.E. "U" symbol.~~     |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~When opening a valve to  |     |     |     |               |
| ~32 | a pressure source, do not  |     |     |     |               |
| .~~ | stand directly in front of |     |     |     |               |
|     | any pressure gauges,       |     |     |     |               |
|     | especially non-safety      |     |     |     |               |
|     | types of pressure          |     |     |     |               |
|     | gauges.~~                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| Hot |                            |     |     |     |               |
| Wa  |                            |     |     |     |               |
| ter |                            |     |     |     |               |
| Hea |                            |     |     |     |               |
| ter |                            |     |     |     |               |
| Saf |                            |     |     |     |               |
| ety |                            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Is the hot water heater    |     |     |     |               |
| 3\. | flushed through the drain  |     |     |     |               |
|     | valve at least once a year |     |     |     |               |
|     | to remove sediment         |     |     |     |               |
|     | build-up?                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Is the safety relief valve |     |     |     |               |
| 4\. | tested once a year to      |     |     |     |               |
|     | ensure proper operation    |     |     |     |               |
|     | (this device protects the  |     |     |     |               |
|     | heater from                |     |     |     |               |
|     | over-pressurizing and from |     |     |     |               |
|     | exceeding 210° F.) ?       |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Is the area around the hot |     |     |     |               |
| 5\. | water heater kept clean    |     |     |     |               |
|     | and free of combustible    |     |     |     |               |
|     | and flammable material?    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Upon leaving for an        |     |     |     |               |
| 6\. | extended time period       |     |     |     |               |
|     | involving days or weeks,   |     |     |     |               |
|     | is the hot water heater    |     |     |     |               |
|     | temperature set at its     |     |     |     |               |
|     | lowest setting.  This will |     |     |     |               |
|     | save money and reduce the  |     |     |     |               |
|     | risk of any problems.      |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Are the manufacturer's     |     |     |     |               |
| 7\. | guidelines followed for    |     |     |     |               |
|     | recommended maintenance    |     |     |     |               |
|     | schedules?                 |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Is the hot water heater    |     |     |     |               |
| 8\. | temperature above 120° F?  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 3   | Is combustible material or |     |     |     |               |
| 9\. | flammable material kept at |     |     |     |               |
|     | least 18" from a hot water |     |     |     |               |
|     | heater?                    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Never leave children     |     |     |     |               |
| ~40 | unattended around a hot    |     |     |     |               |
| .~~ | water heater.~~            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| #   |                            |     |     |     |               |
| ##  |                            |     |     |     |               |
| Com |                            |     |     |     |               |
| pre |                            |     |     |     |               |
| sse |                            |     |     |     |               |
| d-G |                            |     |     |     |               |
| as  |                            |     |     |     |               |
| Cyl |                            |     |     |     |               |
| ind |                            |     |     |     |               |
| ers |                            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Is the protective valve    |     |     |     |               |
| 1\. | cover in place when a      |     |     |     |               |
|     | cylinder is not connected  |     |     |     |               |
|     | to a regulator or          |     |     |     |               |
|     | manifold?                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Are personnel allowed to   |     |     |     |               |
| 2\. | handle oxygen cylinders    |     |     |     |               |
|     | with greasy, oily hands or |     |     |     |               |
|     | gloves? The reaction       |     |     |     |               |
|     | between oxygen and         |     |     |     |               |
|     | hydrocarbons can be        |     |     |     |               |
|     | violent, even when small   |     |     |     |               |
|     | quantities are involved.   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Before raising cylinders   |     |     |     |               |
| 3\. | with cranes, fork trucks,  |     |     |     |               |
|     | or hoists, are they        |     |     |     |               |
|     | secured within suitable    |     |     |     |               |
|     | cradles or skid boxes? Do  |     |     |     |               |
|     | not use ropes or chain     |     |     |     |               |
|     | slings alone for this      |     |     |     |               |
|     | purpose.                   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Never use a gas cylinder |     |     |     |               |
| ~44 | as a roller for moving     |     |     |     |               |
| .~~ | materials or for           |     |     |     |               |
|     | supporting other items.~~  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Are cylinders adequately   |     |     |     |               |
| 5\. | secured in an upright      |     |     |     |               |
|     | position upright on solid, |     |     |     |               |
|     | dry, level footings? Store |     |     |     |               |
|     | preferably outside of      |     |     |     |               |
|     | occupied buildings and     |     |     |     |               |
|     | away from traffic lanes.   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Are cylinders stored in    |     |     |     |               |
| 6\. | the sun shaded during the  |     |     |     |               |
|     | summer? Whenever possible  |     |     |     |               |
|     | store cylinders away from  |     |     |     |               |
|     | sources of intense heat    |     |     |     |               |
|     | (furnaces, steam lines,    |     |     |     |               |
|     | radiators).                |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Is gas, especially         |     |     |     |               |
| 7\. | flammables, poisons, or    |     |     |     |               |
|     | corrosives, stockpiled     |     |     |     |               |
|     | beyond the amount required |     |     |     |               |
|     | for immediate use?         |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Are containers that are    |     |     |     |               |
| 8\. | stored for use in public   |     |     |     |               |
|     | areas, protected against   |     |     |     |               |
|     | tampering and damage?      |     |     |     |               |
|     | Containers stored inside   |     |     |     |               |
|     | or outside shall not       |     |     |     |               |
|     | obstruct exit routes or    |     |     |     |               |
|     | other areas that are       |     |     |     |               |
|     | normally used or intended  |     |     |     |               |
|     | for the safe exit of       |     |     |     |               |
|     | people.                    |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 4   | Do stored cylinders have   |     |     |     |               |
| 9\. | protective caps in place?  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 5   | Are storage baskets for    |     |     |     |               |
| 0\. | smaller cylinders (\<5 L)  |     |     |     |               |
|     | being used? These baskets  |     |     |     |               |
|     | are available              |     |     |     |               |
|     | commercially.              |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Secure both ends of the  |     |     |     |               |
| ~51 | hose with a hose restraint |     |     |     |               |
| .~~ | to prevent whipping in the |     |     |     |               |
|     | event the hose or fitting  |     |     |     |               |
|     | fails. For systems in      |     |     |     |               |
|     | manned areas, support and  |     |     |     |               |
|     | secure the hose and tubing |     |     |     |               |
|     | at least every 7 ft.~~     |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Do not use an open flame |     |     |     |               |
| ~52 | to leak-check a gas        |     |     |     |               |
| .~~ | cylinder; use soapsuds or  |     |     |     |               |
|     | a leak-detection           |     |     |     |               |
|     | solution.~~                |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Remove the talc and dust |     |     |     |               |
| ~53 | from a new hose before     |     |     |     |               |
| .~~ | connecting it.~~           |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Never interchange        |     |     |     |               |
| ~54 | regulators and hose lines  |     |     |     |               |
| .~~ | (with one type of gas for  |     |     |     |               |
|     | another). Explosions can   |     |     |     |               |
|     | occur if flammable gases   |     |     |     |               |
|     | or organic materials come  |     |     |     |               |
|     | in contact with oxidizers  |     |     |     |               |
|     | (e.g., oxygen) under       |     |     |     |               |
|     | pressure.~~                |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Never use oxygen to      |     |     |     |               |
| ~55 | purge lines, operate       |     |     |     |               |
| .~~ | pneumatic tools, or dust   |     |     |     |               |
|     | clothing. Remember, oxygen |     |     |     |               |
|     | is not a substitute for    |     |     |     |               |
|     | compressed air.~~          |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~After installing the     |     |     |     |               |
| ~56 | regulator and before       |     |     |     |               |
| .~~ | opening the cylinder       |     |     |     |               |
|     | valve, fully release       |     |     |     |               |
|     | (turning counterclockwise) |     |     |     |               |
|     | the regulator              |     |     |     |               |
|     | pressure-adjusting         |     |     |     |               |
|     | screw.~~                   |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Keep removable keys or   |     |     |     |               |
| ~57 | handles from valve         |     |     |     |               |
| .~~ | spindles or stems in place |     |     |     |               |
|     | while the cylinders are in |     |     |     |               |
|     | service.~~                 |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Never leave pressure on  |     |     |     |               |
| ~58 | a hose or line that is not |     |     |     |               |
| .~~ | being used. To shut down a |     |     |     |               |
|     | system, close the cylinder |     |     |     |               |
|     | valve and vent the         |     |     |     |               |
|     | pressure from the entire   |     |     |     |               |
|     | system.~~                  |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| ~   | ~~Close the valves on      |     |     |     |               |
| ~59 | empty cylinders to prevent |     |     |     |               |
| .~~ | internal contamination;    |     |     |     |               |
|     | remove the regulators and  |     |     |     |               |
|     | replace the protective     |     |     |     |               |
|     | cap.~~                     |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
| 6   | Are empty cylinders stored |     |     |     |               |
| 0\. | separately from full       |     |     |     |               |
|     | cylinders?                 |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+
|     |                            |     |     |     |               |
+-----+----------------------------+-----+-----+-----+---------------+