Valvtechnologies Leakage Rates vs. Flow Controls Institute Standard (FCI 70-2)
Specification
Leakage Class
Max. Seat Leakage
Test Procedure
Test Duration
FCI 70-2
Class I
No test required (see paragraph 4.2.1 of FCI 70-2)
None
N/A
FCI 70-2
Class II
0.5% of rated valve capacity
Type A (See 5.1)
N/A
FCI 70-2
Class III
0.1% of rated valve capacity
Type A (See 5.1)
N/A
FCI 70-2
Class IV
0.01% of rated valve capacity
Type A (See 5.1)
N/A
FCI 70-2
Class V
5 X 10-4 ml per minute of water per inch of seat diameter per psi differential (5 X 10-12 m3 per second of water per mm of seat diameter per bar differential).
Type B (See 5.2)
N/A
FCI 70-2
Class VI
Leakage as per Table 2 in FCI 70-2
Type C (See 5.3)
N/A
Valvtechnologies
Class III
Zero Visible Leakage
VQP-10 (Hydro Test) Visual Inspection
3 min.s
Valvtechnologies
Class III
Zero Visible Leakage
VQP-10 (Gas Test) Visual Inspection
3 min.s
We test every valve we make according to ANSI
procedures. However, we toughen the standard to zero leakage on both water and
gas. Our standard is zero drops and zero bubbles for a minimum of three minutes.
VALVTECHNOLOGIES TEST PROCEDURE
1)
Prior to testing, the valve is cycled several times and the description of this cycling recorded on the test form after test.
2)
The valve is fitted with the appropriate test fittings or flanges.
3)
High pressure valves are placed in the high-pressure test rack.
4)
The test rack is loaded so that the body joint is not stressed.
5)
To ensure an objective testing procedure, the person who assembles the valve cannot be the person that test certifies the valve.
6)
If a valve is of a size that requires multiple people to assemble then a witness is required to observe and approve the testing procedures and results.
REFERENCE STANDARDS
ASME/ANSI B16.34:
Valves - Flanged, Threaded and Welded End
Flow Control Institute:
FCI 70-2: Control Valve Seat Leakage
Manufacturers Standardization Society:
MSS-SP61: Pressure Testing of Steel Valves
American Petroleum Institute:
API 598: Valve Inspection & Testing
How are we able to achieve such high standards?
Our valves have an integral metal downstream seat. This results in tight shut-off every time!
The integral seat is hard-coated to make it resistant from the attack of catalysts, abrasives and corrosive fluids.
The live-loaded gland packing on the valves
results in the reduced need for maintenance, cuts inspection costs, and meets
the stringent fugitive emission standards today.
Allowable Leakage Rates:
FCI 70-2 Class V & VI; But zero drops or bubbles allowed
Body Design:
should be split body, in line repairable
Seats:
the main (preferred) sealing seat is integral to the end cap, with HVHF ceramet overlay RAM 31 or equivalent. The Rc hardness should be a minimum of 68, at service temperature.
Stem:
the stem should be true blowout proof, no pins or pinned stem designs acceptable material A638 Gr 660 or equivalent. With hard facing a minimum of 68 Rc.
Ball:
410ss with HVHF ceramet overlay RAM 31 or equivalent. Shut-off is to be in accordance with FCI 70-2, and B16.34 1988. With the leakage criteria to be ZERO bubbles and drops over a 3 minute period on all tests.
Bolting:
must conform to B16.34 1988 and ASME Section VIII stress values.
Packing:
to be true live-loaded design, with a minimum of four studs, and a minimum of 6 Belleville washers on each stud.
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