Flanged Double-door Wafer Check Valve Stainless Steel Resilient &
Metal Seated
Dual-plate check valves are bonnetless and mounted between pipe
flanges (wafer style). In this case, the valve includes two
spring-loaded half-moon shaped discs that rotate about their shaft.
The actual designs of these valves vary between design models and
manufacturers. Most have multiple flat seats. The dual-plate check
valve disc has short rotational disc travel and responds quickly to
flow stoppage or reversal, thus the potential for moderate water
hammer does exist. It is somewhat better than the swing check valve
at minimizing potential water hammer, but with a much higher
pressure drop.
Depending on the design, maintenance effort ranges from relatively
simple to difficult. All dual-plate check valves must be removed
from the line to perform maintenance due to the bonnetless design.
The dual-plate check valve also results in a higher pressure drop
when compared to a tilting disc check valve of the same size.
Although most of the wafer check valves are installed between two
flanges, and no need to be flanged type, some other applications
may need flanged type wafer check valve for better alignment of
valves. The flanged valve body could be cast or forged upon
customer's requirement.
Features of Flanged Dual-plate Wafer Check Valves:
One-Piece Body Design
Short Face-to-face
Inline Double Plate
Spring-loaded Disc for Quick Closure
Flanged Wafer End
Applicable Standards of Flanged Dual-plate Wafer Check Valves:
a) Design&Manufacture: API 6D, API 594
b) Face to Face: API 6D, ASME B16.10, EN 558
c) Connection End: ASME B16.5, EN 1092, JIS B2220
d) Test and Inspection: API 6D, EN 12266, API 598
