You can be confident that each and every product is meticulously tested before it leaves our factory. We methodically ensure that from the time the product is in the design process until shipment that our procedures are adhered to, so your knife gate valve will be the very best for the job. Our skilled engineers, craftsmen, and machinists exclusively build knife gate valves. It’s all we do, and we do it well.
Standard Gate Valves
1. Metal Seated
Designed and tested to MSS-SP-81/AWWA C520
150 PSI Cold Working Pressure (CWP), 2” – 24”
50, 75, 100, 125/150 PSI CWP, above 24”
Specifies face to face and flange bolting dimensions
1.1. Body Shell Test
Each valve body is hydrostatically pressure tested at 1.5 times the rated working pressure, with no visible leakage. (Leakage through the packing, gate, seat, and temporary flange gaskets or seals shall not be cause for rejection).
1.2. Seat Test (Leakage)
The seat leakage test is performed with the gate closed and normal test pressure pushing the gate against the seat. The maximum allowable leakage is 40cc per inch of valve diameter per minute, testing with water at 40-PSI.
1.3. Functional Test
Each valve is cycled one complete cycle, from full closed to full open, and from full open to closed to confirm proper operation of valve and accessories (if applicable).
1.4. Gate Test
Valve is tested with the gate closed at the rated pressure. This ensures gate material integrity.
2. Resilient Seated
Designed and tested to AWWA C520.
2.1. Body Shell Test
Each valve body shall be hydrostatically pressure tested at 1.5 times the rated working pressure with no visible leakage. (Leakage through the packing, gate, seat, and temporary flange gaskets or seals shall not be cause for rejection).
2.2. Seat Test (Leakage)
The hydrostatic seat leakage test shall be performed with the gate closed. The maximum allowable leakage shall be zero at the full rated working pressure.
2.3. Functional Test
Each valve shall be cycled one complete cycle, from full closed to full open, and from full open to closed to confirm proper operation of valve and accessories (if applicable).
2.4. Gate Test
Valve is tested with the gate closed at the rated pressure. This ensures gate material integrity.
Custom Gate Valves
Custom testing is available as per the design requirements of the fabricated knife gate valve.
Testing Standards
Manufacturers Standardization Society
MSS SP-81 applies to bonnet less metal seated knife gate valves, 2″ to 24″ size, 150 psi CWP. Sizes above 24″ are not covered under this standard. Additionally, resilient seated knife gate valves and slide knife gate valves are also not covered under MSS SP-81. These products are subject to the individual manufacturer’s internal testing and design standard.
American Water Works Association
AWWA C520 standard describes bonneted, bonnet less and one- and two-piece fabricated stainless-steel and cast ductile-iron body knife gate valves with resilient or metal seats, including tapping knife gate valves, for use in water, wastewater, and reclaimed water systems with pH range from 6 to 12 and a temperature range from 33ºF to 125ºF (0.6ºC to 52ºC). The minimum design pressure shall be 150 psig (1,034 kPa) for nominal sizes 2 in. to 24 in. (50 mm-600 mm), and the minimum design pressure for nominal sizes 30 in. to 96 in. minimum (750 mm-2,400 mm) shall be 25 psig (172 kPa), 75 psig (517 kPa), and 150 psig (1,034 kPa).