API SPEC 6FC:2009 pdf download

API SPEC 6FC:2009 pdf download.Specification for Fire Test forValves with Automatic Backseats.
3.1.7 At the end of the bum period (30 minutes), shut off the fuel.
3.1.8 Immediately determine the amount of water collected in calibrated container (Item 19) to establish total through valve seat leakage. Continue collecting water in the calibrated container (Item 19) for use in establishing the external leakage rate. If the test valve is of the upstream sealing type, the volume of water that is trapped between the upstream seat seal and the downstream seat seal, when the valve is closed, shall be determined before the test is started and identified in the test report. It is assumed that during the test this volume of water would move through the valve, past the downstream seat seal and be collected in the calibrated container. Since this volume has not actually leaked past the upstream seat seal, it may be deducted from the total volume measured in the downstream calibrated container when determining the through valve leakage.
NOTE If the total volume collected downstream during the bum and/or cooldown is less than the body cavity volume, the through leakage can be assumed to have been zero.
3.1.9 Cool the valve (or allow to cool) to 212 °F (100 °C) or less. Record reading on sight gauge (Item 4), and calibrated container (Item 19). Cooling may, at the manufacturer’s option, be natural or forced.
3.1.10 The following low-pressure test is required only for API 6D valves with ratings of Class 600 and lower. Decrease the test pressure to the low test pressure value shown in Table 1. Measure the through valve and external leakage over a 5-minute period.
3.1.11 If the step in 3.1.10 was performed, increase pressure on test valve to the high test pressure value in Table 1.
3.1.12 Verify that backseating has occurred by monitoring for (and measuring) leakage at a test port above the backseat, for a period of 5 minutes.
3.1.13 Vent pressure.
NOTE Venting pressure is a change made for safety reasons, and may be omitted at the manufacturer’s option, or for previouslyquaIified valve designs.
3.1.14 Rework the stuffing box as required. Rework shall be limited to replacement of packing and eutectic washer with parts of the same design and materials. Rework of the stuffing box may include the cleaning out of charred or burnt packing, and light honing or polishing of the sealing area of the stem and stuffing box.
3.1.15 Reapply pressure.
3.1.16 Open the test valve against the high test pressure differential. The valve shall be moved to a partly open (approximately half-way) position. Close the shutoff valve (Item 16). Vent the piping and test valve body cavity to remove air or steam.
3.1.17 Measure and record external leakage for a period of 5 minutes after valve is in the open position at high test pressure.
3.2 Test Adjustments
The stuffing box may be reworked per 3.1.13. No other part of the test valve may be adjusted during the test period. The test system may be adjusted during the test period to keep the test within the limits specified herein.
4 Performance Requirements
4.1 Through Leakage (High Test Pressure)—During Burn Period
The maximum through seat (does not include bonnet and stem) leakage shall not be greater than the value shown below (see 3.1.8.):
Burn Period 30 minutes
Rate 400 ml/in./min 1(15.7 mI/mm/mm)
4.2 External Leakage (High Test Pressure)—During Burn and Cooldown Period (Valve in Closed Position)
The maximum external leakage, not including seat leakage, shall not be greater than the value shown below (see 3.1.8 and 3.1.9):
Test Duration 30 minutes ptus time to cool down to 212 °F (100 °C)
Rate 100 ml/in./min 1(3.9 mI/mm/mm)
4.3 Through Leakage (Low Test Pressure)—After Cooldown
The maximum through seat (does not include bonnet and stem) leakage shall not be greater than the value shown below (see 3.1.10):
Test Duration 5 minutes
Rate 40 ml/in./min 1(1.6 mI/mm/mm)
4.4 External Leakage (Low Test Pressure)—After Cooldown (Valve in Closed Position)
The maximum external leakage not including seat leakage shall not be greater than the value shown below (see
3.1.10):
Test Duration 5 minutes
Rate 20 ml/in./min 1 (0.8 mI/mm/mm)
4.5 External Leakage (High Test Pressure)—During the Backseat Test and Rework of the Stuffing Box
After draining any water which may have entered the stuffing box before backseating was complete, no leakage is acceptable (see 3.1.12 and 3.1.13):
4.6 Operation of Test Valve After Fire Test
The valve shall be capable of being unseated from the closed position against high test pressure differential (see Table 1). The valve shall be moved to the open position one time (as specified in 3.1.14).