BS 6364

[sks4338]

I think if you are to apply BS 6364, it is in addition to API 598.

I think testing will go as follows.

You test the valves in accordanc with API 598.
(Let's say we are talking about Group 2.2 material
like A182-F316. We are going to test hydrostatically,
no pneumatic test that appears in API 598.)

a). Shell test pressure = 275 * 1.5 = 425 PSIG (with nearest 25 psig increment)
b). Seat test pressure = 275 * 1.1 = 325 PSIG (with nearest 25 psig increment)

And test them again with BS 6364.
c). Shell strength test (In accordance with API 598)
- you pass this test, because you tested in a).

d). Shell leak test
e). Seat leak test at 6.9 barg.
- you pass this test, because you tested in b).

f). Cryogenic prototype test
-196'c, helium, 275 psig

What I think is you take test a), b), d), f).

Am I right?

 

[LSThill]

Whether the valve is to be low temperature tested or cryogenic tested, the test
method will be in accordance with *SPE 77/306 (latest revision) or similar
procedure e.g. BS 6364. The sequence of testing per SPE 77/306 is as follows:
• Hydrotest at ambient temperature Acceptance standard API 598
• Pneumatic test at ambient temperature Acceptance specification SPE 77/306
• Cryogenic/Low temperature testing

Coolant Selection:
Cryogenic testing at -196°C: Immersion of valve in liquid nitrogen.
Low temperature testing -46°C: Immersion in liquid nitrogen vapour.
Intermediate temperature testing: Immersion in liquid nitrogen or liquid nitrogen vapour.

Temperature Control:
Temperature is monitored by the use of thermocouples located both internally
and externally of the valve body and internally and externally of the test tank.
Once the required valve temperature has been achieved and stabilised the
pressure test commences.

Selection of leak test medium:
Cryogenic ie. -196°C: pure helium.
Low temperature ie. -46°C: 99% helium/1% nitrogen mix or pure helium.
Intermediate temperature: pure helium, or 99% helium/1% nitrogen mix
dependent on test temperature.

Test Method – SPE 77/306:
Pressure within the test valve is increased in 3 equal increments and
seat leakage is measured using a series of calibrated flowmeters.

The maximum pressure at which the valve is tested is limited by the
Cold Working Pressure (CWP) as designated in ANSI B16.34 for the rating
of valve under test.

Shell (body) Leakage Test:
Following seat leakage test, the valve is removed from the tank and the valve
body integrity is tested whereby the body cavity is pressurised and a shell leak
detection test carried out using a Helium Mass Spectrometer. The detection limit
for acceptance is 5 x 10-4 ml/sec, this being defined as zero leakage.

Operational Test:
The test valve can be operated 5 times (open and closed) at the maximum allowable rated seat test pressure. The open and close torque forces can be recorded.

• Test Reports
All observations, data and results shall be recorded in sequence with dates and times into a single Test Report document.