01
Lug Type Dual Plate Check Valve
Industry Standards
ASME B16.1, B16.5, B16.24, B16.34, B16.47 and B31.1
API 594 and 598
MSS-SP-25, MSS-SP-55
API 6A and 6D (as applicable)
MSS-SP-61 (standard for the resilient seated, metal seated when required)
NACE MR-01-75 (Latest Edition, when required)
Technical Data
Size range : 2” thru 60”
Pressure Classes : ASME 125 thru 2500
Temperature Range : -46°F to 1100°F
Design Features
Retainer less design eliminates fugitive Emissions. Is firesafe by design.
A more compact Light weight design Is 80 to 90% lighter than conventional full-body swing check valves.
Simplifies piping for an easier, less costly installation. Optimum space utilization for simplified piping.
Spring-loaded, dual plate design has Very low cracking pressure.
Discs open 85° to ensure a low pressure drop.
Positive sealing under most operating conditions. The valve closes before the flow reverses at zero velocity.
With the spring assisted closing, water Hammer is all but eliminated.
By design the valve is inherently non-slamming. This is due to the plates closing before the media flow reverses.
The flanged check valve can be installed in the horizontal and vertical up positions. For vertical down installations please contact WELCO.
Main parts and material list
| NO. | PART NAME | WCB / A105 | WCB / A105 | LCC / LF2 | LCC / LF2 | CF8 / F304 | CF8 / F304 Trim #2S | CF8M / F316 | CF8M / F316 |
| Trim #8 | Trim #1 | Trim #10 | Trim #12 | Trim #2 | Trim #10 | Trim #12 | |||
| 1 | BODY | WCB/A105 | WCB/A105 | LCC/LF2 | LCC/LF2 | CF8/304 | CF8/304 | CF8M/316 | CF8M/316 |
| 2 | BODY SEAT | STL | 13Cr | SS316 | STL | as same as body | STL | as same as body | STL |
| 3 | DISC | CF8/CA15 | CF8/CA15 | CF8M | CF8M | CF8 | CF8 | CF8M | CF8M |
| 4 | DISC SEAT | as same as disc | |||||||
| 5 | HOLDER | CF8/CA15 | CF8/CA15 | CF8M | CF8M | CF8 | CF8 | CF8M | CF8M |
| 6 | BEARING | SS410 | SS410 | SS316 | SS316 | SS304 | SS304 | SS316 | SS316 |
| 7 | SPRING | INCONEL X-750 | |||||||
| 8 | HINGE PIN | SS410 | SS410 | SS316 | SS316 | SS304 | SS304 | SS316 | SS316 |
| 9 | STOP PIN | SS410 | SS410 | SS316 | SS316 | SS304 | SS304 | SS316 | SS316 |
| 10 | LOCK | A105 | A105 | SS316 | SS316 | SS304 | SS304 | SS316 | SS316 |
| 11 | SCREW | SS304 | SS304 | SS316 | SS316 | SS304 | SS304 | SS316 | SS316 |
| 12 | LIFTING LUG | CARBON STEEL | |||||||