Approvals: 1st Level 2nd Level 3rd Level 

National Institute for Occupational Safety and Health 

National Personal Protective Technology Laboratory 

P.O. Box 18070 

Pittsburgh, PA 15236 

Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005

DETERMINATION OF LEAKAGE OF DRINKING TUBE AND ACCESSORIES 

FOR RESPIRATOR FACEPIECES 

STANDARD TESTING PROCEDURE (STP) 

1. PURPOSE

 

This test establishes the procedure for ensuring that the level of protection provided by the 

leakage of drinking tube and accessories test requirements on respirator facepieces submitted for 

Approval, Extension of Approval, or examined during Certified Product Audits, meet the 

minimum certification standards set forth in 42 CFR Part 84, Subpart G, Section 84.63(a)(c)(d); 

Volume 60, Number 110, June 8, 1995. 

2. GENERAL

This STP describes the Determination of Leakage of Drinking Tube and Accessories for 

Respirator Facepieces test in sufficient detail that a person knowledgeable in the appropriate 

technical field can select equipment with the necessary resolution, conduct the test, and determine 

whether or not the product passes the test. 

3. EQUIPMENT/MATERIAL

3.1. The list of necessary test equipment and materials follows: 

 3.1.1. Vacuum Source to supply a steady suction of 75 mm per minute or 3 inches of 

water. 

3.1.2. Open end water manometer, capable of holding a 6" vacuum of water. 

 3.1.3. Gilibrator Primary Flow Calibrator System: Gilibrator control unit p/n 800268 

with Thermal Printer DPU-40 p/n D800286, Bubble Generator (low), Range 1-

250cc, p/n C-800274, Bubble Generator Soap Solution p/n 800450. 

 3.1.4. Drinking tube holder to keep the tube valve, seat or seal in the proper position 

while the suction is applied. This holder is not specific and is modified with each 

valve, seat, or seal that is submitted. Equipment used quite often are funnels in 

various sizes (dependent on size of valves) that allow the valve, seat, or seal to be 

sealed in with hot melt glue and/or wax on both sides to obtain an airtight seal.

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 2 of 9 

 3.1.5. Hot melt glue gun. 

 3.1.6. Heating plate and 200 ml beaker 

3.1.7. Miscellaneous Equipment – Hose Clamps, 1/4 inch OD Hose, eye droppers, 3-

Way "T" hose connector and small brush. 

 3.1.8. Vacuum bottle (approx. 1 gal.) with three tube connections for house vacuum 

source, air inlet valve, and tubing to rest of system. This vacuum bottle 

apparatus allows an accurate control of small negative pressures to the system. 

 3.1.9. Short hose with pinch clamp for control of flow. 

 3.1.10. Bees’ wax. 

 3.1.11. Timer used to time the leakage rate. 

4. TESTING REQUIREMENTS AND CONDITIONS

4.1. Prior to beginning any testing, all measuring equipment to be used must have been 

calibrated in accordance with the manufacturer's calibration procedure and schedule. At 

a minimum, all measuring equipment utilized for this testing must have been calibrated 

within the preceding 12 months using a method traceable to the National Institute of 

Standards and Technology (NIST). 

4.2. Normal laboratory safety practices must be observed. This includes safety precautions 

described in the current ALOSH Facility Laboratory Safety Manual. 

 4.2.1. Safety glasses, lab coats, and hard-toe shoes must be worn at all times. 

4.2.2. Work benches must be maintained free of clutter and non-essential test 

equipment. 

4.2.3. When handling any glass laboratory equipment, lab technicians and personnel 

must wear special gloves which protect against lacerations or punctures. 

5. PROCEDURE 

Note: Reference Section 3 for equipment, model numbers and manufacturers. For calibration 

purposes use those described in the manufacturer's operation and maintenance manuals. 

 5.1. Follow individual instruction manuals for set up and maintenance of equipment used in 

this procedure prior to beginning testing. Malfunctioning equipment must be repaired or 

replaced and properly set up and calibrated before starting all tests. 

. 

5.2. Use submitted drinking tube valves, valve seats, or seal assemblies or remove these 

drinking tube valves, valve seats, or seal assemblies from the respirators without 

distortion of the drinking tube valves, valve seats, or seals. 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 3 of 9 

5.3. Hot melt glue on the back side of the valve, seat, or seal assembly and position it into the 

funnel. Carefully wax in place to seal any air holes. Hot melt a larger funnel to the 

smaller funnel. Make sure the funnel or fixture will cover the valve assembly yet not 

block the operation of the valve itself. Wax to seal and fill all areas. (See Fig. 1.) 

5.4. Set up test equipment as shown in Figure 2. Check the water level in the manometer. If 

the water level is not at zero, remove the top from the unconnected end and slowly add 

drops of distilled water until it reaches zero. 

5.5. Test the system for leaks. (See Fig. 2.) 

5.5.1. Clamp off hose number 9 completely. Apply a six inch vacuum to the system 

using the house vacuum valve. If the house vacuum is insufficient to maintain 

six inches, restrict the flow through the system using a pinch clamp at 2. 

5.5.2. Clamp hose number 5 off completely. If the manometer starts to fall, then there 

is a leak at the manometer connection and it must be corrected before proceeding 

to the next step. 

5.5.3. Remove the clamp from hose 5. Clamp off hoses 7 and 3 in that order. If the 

manometer falls, then there is a leak around the "T" connector and it must be 

corrected before proceeding to the next step. 

5.5.4. Remove the pinch clamps from hoses 3 and 7. Replace the clamp on hose 3. If 

the manometer falls, then there is a leak around the valve holder and it must be 

corrected before conducting the actual leakage test. 

5.5.5. Remove all pinch clamps from the interconnecting hoses. 

5.5.6. Turn the vacuum off. 

5.5.7. Completely open pinch clamp number 2. (See Fig. 2.) 

5.6. Allow the bubble generator of the Gilibrator to wet the cell by applying a low flow 

vacuum to the generator. Reset the control unit. 

5.7. Attach the funnel/exhalation valve assembly to the Gilibrator and apply a 1 inch vacuum 

of water. 

5.8 Allow the generator to receive and record the bubble reading. The reading will print out 

in ml/min. 

 5.9. Repeat steps 5.3 through 5.8 for the other two valves, seats, or seal assemblies. 

6. PASS/FAIL CRITERIA

6.1. The criterion for passing this test is set forth in 42 CFR Part 84, Subpart G, Section 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 4 of 9 

84.63(a)(c)(d), Volume 60, Number 110, June 8, 1995. 

 6.2. This test establishes the standard procedure for ensuring that: 

 84.63 Test requirements; general. 

(a) Each respirator and respirator component shall when tested by the applicant and by 

the Institute, meet the applicable requirements set forth in subparts H through L of this 

part. 

(c) In addition to the minimum requirements set forth in subparts H through L of this 

part, the Institute reserves the right to require, as a further condition of approval, any 

additional requirements deemed necessary to establish the quality, effectiveness, and 

safety of any respirator used as protection against hazardous atmospheres. 

(d) Where it is determined after receipt of an application that additional requirements will 

be required for approval, the Institute will notify the applicant in writing of these 

additional requirements, and necessary examinations, inspections, or tests, stating 

generally the reasons for such requirements, examinations, inspections, or tests. 

 6.3. Drinking tube valve, seat, seal leakage test. 

(a) Dry drinking tube valves, valve seats, or seals will be subjected to a suction of 75 mm. 

water-column height while in a normal operating position. 

 

 (b) Leakage between the valve and valve seat shall not exceed 30 milliliters per minute. 

 

 

7. RECORDS/TEST SHEETS

7.1. All test data collected will be recorded on the DETERMINATION OF DRINKING 

TUBE LEAKAGE, FOR RESPIRATOR FACEPIECES test data sheet. 

7.2. All videotapes and photographs of the actual test being performed, or of the tested 

equipment shall be maintained in the task file as part of the permanent record. 

7.3. All equipment failing any portion of this test will be handled as follows: 

7.3.1. If the failure occurs on a new certification application, or extension of approval 

application, send a test report to the RCT Leader and prepare the hardware for 

return to the manufacturer. 

7.3.2. If the failure occurs on hardware examined under an Off-the-Shelf Audit the 

hardware will be examined by a technician and the RCT Leader for cause. All 

equipment failing any portion of this test may be sent to the manufacturer for 

examination and then returned to NIOSH. However, the hardware tested shall be 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 5 of 9 

held at the testing laboratory until authorized for release by the RCT Leader, or 

his designee, following the standard operating procedures outlined in Procedure 

for Scheduling, and Processing Post-Certification Product Audits, RB-SOP0005-00. 

8. ATTACHMENTS

 8.1. Drinking Tube Valve Holder Assembly and Bench Top Set-Up (Figures 1 and 2). 

 

 8.2. Description of Bench Top Set-Up in Figure 2. 

 8.3. Data Sheet. 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 6 of 9 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 7 of 9 

Description of Schematic Diagram of the System 

1. Vacuum bottle (approx. 1 gal.) with three tube connections for house vacuum source, air 

inlet valve, and tubing to rest of system. This vacuum bottle apparatus allows an accurate 

control of small negative pressures to the system. 

2. Short hose with pinch clamp for control of flow. 

3. 1/4 in. O.D. hose approximately 2 1⁄2 feet in length. 

4. 3-Way "T" hose connector. 

5. 1/4 in. O.D. hose approximately 2 feet in length. 

6. Open end water manometer. 

7. 1/4 in. O.D. hose 3 to 4 inches in length. 

8. Drinking Tube Valve holder. 

9. 1/4 in. O.D. hose approximately 2 1⁄2 feet in length. 

10. Gilibrator flow system. 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 8 of 9 

RB - RESPIRATOR CERTIFICATION TEAM 

DRINKING TUBE VALVE LEAKAGE DATA SHEET (CFR 84.63 ) STP No.: [ ] 

 Task Number: TN- Manufacturer: Item Tested: 

Requirement: Shall not exceed 30mm/min. at a suction of 75mm of water. 

Valve #1: 

Event No. Leakage-mm. Time/Min. Leakage-mm/Min.

 1. 

 2. 

 3. 

 Average: mm/Min. 

Valve #2: 

Event No. Leakage-mm. Time/Min. Leakage-mm/Min.

 1. 

 2. 

 3. 

 Average: mm/Min. 

Valve #3: 

Event No. Leakage-mm. Time/Min. Leakage-mm/Min.

 1. 

 2. 

 3. 

 Average: mm/Min. 

 Overall Results: Pass Fail Comment: 

 Was all testing equipment in calibration throughout all testing: Yes No 

 Signature: Date: 

RB - RESPIRATOR CERTIFICATION TEAM 

 DRINKING TUBE VALVE LEAKAGE DATA SHEET (CFR 84.63 ) STP No.: [ ] 

 Task Number: TNManufacturer: Item Tested: 

Additional Comments: 

Signature: Date: 

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Procedure No. RCT-APR-STP-0014 Revision: 1.1 Date: 6 June 2005 Page 9 of 9 

Revision History 

Revision Date Reason for Revision 

1.0 11 July 2001 Historic document 

1.1 6 June 2005 Update header and format to reflect lab move from Morgantown, WV 

No changes to method 

 

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