Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 1 of 9

Test Procedure For Testing of Cryogenic Valves

Based on BS 6364, API 598 and EPA Method 21

Revised By: ____________________________

Vahe Najarian, Eng. Corporate Manager, R&D and Engineering Support

Reviewed By: ____________________________

Christian Beguian, Eng. R&D Manager

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 2 of 9

1. INTRODUCTION

The following procedure covers the testing for sealing and operability of a) Cryogenic valves tested at -196 °C (-320 °F). b) Low temperature valves, tested at -46 °C (-50 °F).

This procedure is based on BS 6364, API 598 and EPA Method 21, to the extent applicable and specified herein.

2. TEST PLAN

The test comprised of the following tests at ambient temperature, then cryogenic or low temperature and again at ambient temperature as given below:

2.1 Ambient Temperature: - Shell and seat test according to API 598.

- System proving seat test.

2.2 Cryogenic or low - Repeat system proving seat test. Temperature:

- Operational tests for opening and closing torques. - Low pressure seat test. - High pressure seat test at incremental pressures

up to high seat test pressure. 2.3 Ambient Temperature - Repeat system proving seat test.

- External leakage test. - Visual examination.

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 3 of 9

3. TEST TEMPERATURES 3.1 Ambient temperature: Test performed at 25 ± 10 °C (77 ± 18 °F).

3.2 Cryogenic temperature: Test performed at -196 ± 5 °C (-320 ± 9 °F).

3.3 Low temperature: Test performed at -46 ± 3 °C (-50 ± 6 °F). 4. SEAT TEST PRESSURES 4.1 Low pressure seat test: Test at 80 psig. 4.2 System proving seat test: Test at high seat test pressure (one increment), as per

table below. Exception: For soft seated ball valves at ambient temperature, Test at low seat test pressure (as per API 598).

4.3 High pressure seat test: Raise the pressure in increments up to seat test pressure

as given in the table below. Measure and record the leakage rate at each pressure interval.

Pressure Class (ASME B16.34)

High Seat Test Pressure*

(psi)

Increment of Test Pressure

(psi) 150 275 100 300 720 250 600 1,440 375 800 1,800 375 900 2,000 400

1500 2,000 400

*Note: If the valve maximum permissible working pressure at 20°C or the valve seat rating is less than that shown in above table, use the lower value as the high seat test pressure.

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 4 of 9

4.4 Duration of Seat Test: 10 minutes minimum at each pressure interval. 4.5 Direction of Seat Test: 4.5.1 Globe and gate valves: Seat test is conducted in the normal flow direction for the

valve. 4.5.2 Check valves: Seat test is conducted in the reverse flow direction of the

valve.

4.5.3 Ball and Butterfly valves: Seat test is conducted in preferred direction.

4.5.4 Bidirectional sealing: For valves, which are capable of sealing in both directions the normal flow (or preferred) direction only shall be tested. Upon specific customer request and agreement, each sealing direction can be tested separately.

5. TEST SEQUENCE 5.1 Ambient Temperature Tests: 5.1.1 Perform shell and seat test according to API 598. 5.1.2 Purge the valve using helium gas. 5.1.3 Perform initial system proving test. 5.2 Cryogenic or Low Temperature Tests: 5.2.1 Cool down the valve. When the valve has reached the required test temperature,

allow for one hour of stabilization time, then testing may proceed. 5.2.2 Repeat initial system proving test. 5.2.3 Cycle the valve open-close 5 times. Record the operating torques for the first and last

cycle. 5.2.4 Close the valve and pressurize the valve in the seat test direction to 80 psig. Wait at

least 10 minutes to stabilize helium temperature.

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 5 of 9

5.2.5 Record seat leakage rate. 5.2.6 Increase the pressure in stages to the maximum seat pressure as described in

Section 3.3. At each test pressure, wait at least 10 minutes to stabilize the gas temperature.

5.2.7 Record the seat leakage rate at each of the pressure intervals. 5.3 Ambient Temperature Tests after Cryogenic Tests: 5.2.1 Remove the valve from liquid nitrogen and let it warm back to ambient temperature. 5.3.2 Repeat initial proving test. 5.4 External Leakage Test 5.4.1 With the valve half-open, pressurize the valve to 90 psig helium gas.

5.4.2 Use the helium mass spectrometer to sniff the leakage around the valve for the entire

test duration. Mass spectrometer is to be calibrated (before use) as per the equipment manufacturers procedure. A one-time packing-bolt, bonnet-bolt, and end-flange-bolt re-torque is allowed during testing.

Valve Size Test Time (minutes) 3” to 16” 6

> 16” 9 5.4.3 Retainerless design dual plate check valves are exempt from external leakage test. A

retainerless design has no openings through the body, i.e. no packing and no body/bonnet gasket.

5.5 VISUAL EXAMINATION

After successful testing, the test flanges on the valve shall be removed and the disc and seat sealing area shall be visually inspected to the extent possible (practical only on large valves).

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 6 of 9

6. ALLOWABLE LEAKAGE RATES 6.1 Seat leakage:

Allowed Seat Leak (standard cc/minute/inch) Valve Type Class 150, 300 & 600 Class 800, 900 & 1500

Ball, gate, globe & Butterfly: 150 200 Check: 300 400

6.2 External leakage: at no time throughout the duration of the test, shall a reading of

>1x10-4 cc/sec or 50 PPM be sustained for more than ten (10) seconds.

7. TEST SET-UP for CRYOGENIC TESTS:

7.1 The valve to be tested is supported in a stainless steel tank. The sides and the

underside of the tank are insulated on the outer faces. The valve is held between blind flanges with small bore piping leading to the fixtures to supply the pressurising media. Stem position is vertical for gate, globe, ball and butterfly valves. Check valves (swing, dual plate, etc.) may be tested in either vertical or horizontal disc position.

7.2 The valve temperature is lowered by filling the tank with the cooling medium (see

below table), to a level above the body-bonnet bolting. The valve temperature is monitored by a thermocouple, installed on the valve body or end plate. The test is commenced when the valve temperature is stabilized within the test temperature tolerances, as indicated by the thermocouples.

Cooling Medium Test Valve @ Temperature Liquid Nitrogen. Cryogenic @ -196 °C (-320 °F). Dry ice, mixed with a heat transfer fluid (eg. Ethylene Glycol).

Low temperature @ -46 °C (-50 °F).

7.3 Test gas (see below table) from a fully charged bottle is used to provide test pressure

on the inlet side of the valve. The opening and closing torques for the valve are measured using a torque wrench.

Test Gas Test Valve @ Temperature Minimum 97% pure Helium. Cryogenic @ -196 °C (-320 °F). Minimum 97% pure Helium or Nitrogen, mixed with 1% Helium (for external leak detection).

Low temperature @ -46 °C (-50 °F).

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 7 of 9

7.4 All instruments (flowmeter, pressure gauges, torque wrench, etc.) are to be calibrated.

7.5 A typical test rig is shown on sketch ‘A’.

8. Flowmeters, Flowmeter Calibration, Seat Leak, and Correction Factors:

8.1 Flow meter type: Any type may be used, provided that it can be calibrated.

8.2 Flow meter calibration: Are to be calibrated for the test gas (Helium or Nitrogen). Or, the manufactures correction factor is to be used to relate the calibration gas (typically Nitrogen) to the test gas.

8.3 Seat leak: Allowed seat leak is measured at the flowmeter, and are at standard atmospheric conditions.

8.4 Temperature Correction: Temperature of exiting test gas is to be measured (before

flow meter). “Charle’s law” is to be used for temperature correction. I.e. V1*T2=V2*T1. Therefore, Q1*T2=Q2*T1. Where: V1 is test gas volume exiting the flowmeter. V2 is test gas volume expressed (corrected) at ambient temperature. T1 is test gas temperature exiting the flowmeter (°R). T2 is the standard ambient temperature (528 °R).

Q1 is test gas flow exiting the flowmeter (cc/min). Q2 is test gas flow exiting the flowmeter and expressed (corrected) at

ambient temperature (standard cc/min).

8.5 Pressure Correction: Pressure of the exiting test gas is near atmospheric, and assumed to have negligible effect. Therefore, measurement of exiting pressure, as well as correction is not required.

8.6 Exemption: Some flow meters (eg. Electronic mass flow meters) are not affected by pressure or temperature changes, and can be calibrated to provide a direct reading at standard conditions. When such a flow meter is used, test gas pressure and temperature (as well as correction) at the flow meter is not required.

Research & Development Dept.

Test Procedure for Testing of Cryogenic Valves Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 8 of 9

Research & Development Dept.

Test Report for Testing of Cryogenic Valves

Based on BS 6364, API 598 and EPA method 21

RD-416 Rev. E

DATE: Revised BY: REV.: PAGE No:

Feb 22, 2007 V. Najarian E 9 of 9

Velan Order/Item/Position: Test Date & No.: Customer Order No.: Valve Tag No.: Project Name: Test Temperature Valve Fig. No.: Cooling Medium Valve Type/Size/Class: Test Gas: ≥ 97% Pure Actuator Type & HW ∅: (in) Allowed Seat Leak: ≤ scc/min Flowmeter Type: Allowed External leak: ≤1x10-4 cc/sec or 50 ppm

Note: scc/min = standard cm3/minute AMBIENT TEMPERATURE – INITIAL PROVING TEST: Test Pressure (psig) Duration of Seat Test (min) Seat Leak Rate (scc/min)

CRYOGENIC or Low Temp TEST: Valve stabilization Temperature (°F): Time:

Initial Proving Test Pressure (psig) Duration (min) Seat Leak (cc/min)

Cycle Opening Torque (ft.lbs) Closing Torque (ft.lbs) 1st Valve stroked 5 times

Record Operating Torques 5th

Low Pressure Seat Test (psig) Duration (min) Seat Leak (cc/min) Incremental Seat Test:

Increment Pressure (psig) Duration (min) Measured Seat Leak (cc/min) Corrected Seat Leak (scc/min)

1st 2nd 3rd 4th 5th

Ambient Temperature Tests

Initial Proving Test Pressure (psig) Duration (min) Seat Leak (scc/min)

External Leakage Test Pressure (psig) Duration (min) Valve Body Bonnet Joint Stem Seal

PASS (√ ) Visual Examination or Comments:

FAIL ( X )

Tested By Approved By Customer Witness