API RP 14H:2007 pdf download
API RP 14H:2007 pdf download.Recommended Practice for Installation, Maintenance and Repair of Surface Safety Valves and Underwater Safety Valves Offshore.
6.2.2 USV Pressure Holding Test
Each operator should use a method appropriate to his system to demonstrate the pressure integrity of the USV and quantify buildup rates. The following are two options offered for general guidance only:
a. Option 1: Perform test as in 6.1.2.
b. Option 2:
1. Shut-in well and USV as for operation test (see 6.1 .2a and 6.1 .2b) and close downstream header or flowline valve.
2. With pressure on upstream side of the USV, measure pressure buildup in the flowline versus time. If the absolute pressure
buildup in the confined line segment downstream of the USV is in excess of that which represents a flow rate of 400 cubic
centimeters per minute (0.4 cubic decimeter per minute) of liquid or 15 standard cubic feet per minute (611.6 cubic meters per
day) of’ gas, the USV should he repaired or replaced. An example with calculations is given in Appendix A. Test duration
should be a minimum of 5 minutes.
3. Return well to production.
6.3 TESTING AFTER ONSITE REPAIRS
6.3.1 General
After onsite repair. a SSV/USV should be subjected to the appropriate test(s) listed in 6.3.2 to demonstrate proper assembly and operation. When repair on the SSV/USV actuator does not affect the SSV/USV valve, testing may be limited to that required in 6.1.1 or 6.2.1.
The test results should be documented on an SSV/USV Functional Test Data Sheet for Onsite Repairs similar to the example shown in Exhibit 3.
6.3.2 Testing
Recommendations for testing SSVs/USVs following onsite repairs are stated below. Testing may be limited according to onsite repairs performed.
6.3.2.1 Onsite repairs where the SSV/USV actuator pressure containing seals are broken or disturbed. The SSV/USV actuator should be tested for leakage using the SSV/USV actuator media. Test pressure should be normal field operating supply pressure. No leakage is allowed.
6.3.2.2 Onsite repairs that might ajfict the alignment of the gate (‘plug) and seats. The SSV/USV valve should be opened and checked visually or, if possible, with a drift mandrel for proper alignment.
6.3.2.3 Onsite repairs that might affct operation of the SS V/US V The complete assembly should be tested for operational integrity; cycle the assembly fully open and fully closed three times with the SSV/USV valve body at ambient pressure or at well- head shut-in tubing pressure (SITP) with no flow. (If equipment through the first downstream block valve will not withstand full wellhead SITP, conduct this test at the working pressure of the downstream equipment.)
6.3.2.4 Onsite repairs that require breaking or disturbing a pressure containing seal in the SS V/US V valve. The SSV/USV valve seals should be tested for leakage with the SSV/USV in a fully or partially open position and with the SSV/USV valve body exposed to maximum wellhead SITP. Test duration should be a minimum of 5 minutes with no leakage. (If equipment through the downstream block valve will not withstand full welihead SITP. conduct this test at the working pressure of the downstream equipment.)
6.3.2.5 Onsite repairs that mnight a/ftc! the SSV/USV valve seat seal. The SSV/USV valve seat should be tested according to
6.1 or 6.2 following the test prescribed in 6.3.2.4 above.
7 Failure Reporting
User Recommendation: The operator of SSV/USV equipment repaired to this standard should provide a written report of equipment failure to the manufacturer. This report should include, as a minimum, the information in Exhibit 1 and a copy of the SSV/USV Repair Record Sheet (Exhibit 2).
For installations inaccessible to leakage flow monitoring or for installations piped into large volume flowlines or vessels (10 barrels or more), leakage may be monitored as a function of pressure increase per unit of time. For example, in the case of a long flowline, the flow may be monitored by closing the USV, bleeding the pressure to ambient in the tlowline segment and closing the first convenient isolation valve. Pressure increase in that isolated volume can then be monitored per unit of time; if the resulting increase is higher than specified in 6.2.2, Option 2, the valve should be repaired or replaced.
Note: The following examples are merely examples for illustration purposes only. [Each company should develop its own approach.] They are not to be considered exclusive or exhaustive in nature. API makes no warranties, express or implied for reliance on or any omissions from the information contained in this document.
