Standard Features
Integral Flapper and Shaft
HY-GRADE's flapper and shaft are designed as an integral component with large diameter shafts to provide strength at a critical location. In contrast, typical check valves have multiple components which are assembled together using bushings, nuts, bolts, and hinge pins. Over time these multiple components tend to come apart leading to valve failure. HY-GRADE's integral flapper and shaft design has a long and proven history of providing reliable service in the harshest of applications.
High Flow with Low Pressure Drop
HY-GRADE's Large Unobstructed Bore provides maximum flow capacity with extremely low pressure drops. The unobstructed bore also allows HY-GARDE check valves to be used in slurry, high consistency or abrasive applications.
Positive Shut-Off
The flapper/shaft component is housed in a retainer slot which allows the flapper to swing freely without the use of journals and bushings. This allows the flapper to cycle closed without interference and the line pressure is distributed evenly across the flapper for a 360° positive seal.
Instant Sealing and Anti-Chatter Operation
A double wound torsion spring assists the flapper closure for instant sealing and anti-chatter operation. The spring is securely held in the valve body on an independent pin and is completely shielded from the flow.
Renewable Seats
HY-GRADE check valves have a renewable seat insert for low cost and easy repair.
Improved Metal-to-Metal Seal
HY-GRADE developed the WedgeSeal to improve metal-to-metal sealing. As shown, the WedgeSeal has seating surfaces which are machined at slight angles. As a result, positive shut off is obtained due to the wedging action of the sealing surfaces. Note, the sealing surfaces are machined only at slight angles to prevent the valve from sticking in the closed position in high back pressure applications. The WedgeSeal technology pioneered by HY-GRADE makes HYGRADE metal seated check valves excellent for both low and high pressure applications.
Secure Soft Seals
Soft seals are mechanically held in an insert for secure and bubble tight sealing. In addition, there is a metal-to-metal back up seal as tested by API Fire tests. The soft seal is not in the direct flow and cannot be lost due to suction, even at high working pressure or extreme conditions
Retainerless
A standard feature of HY-GRADE check valves is a retainerlass design. There are no external holes for shafts therefore there are no external leak paths or fugitive emissions.
Fire Safe
The design of the standard HY-GRADE check valve assures positive shut off under fire conditions and is certified to API 6FA and 6FD. Both soft seated and metal seated HY-GRADE check valves were tested by accredited independent laboratories at temperatures to 1200-1800° F and pressures up to 3750 psi. All the HY-GRADE check valves tested passed the external and internal leakage requirements.
The API Fire tests also demonstrated that HY-GRADE check valves provide a positive shutoff after the removal of the resilient seating material as required by U.S. Coast Guard Category "A" and "Positive Shutoff" valves.
Optional Features
Tilt Seat / Non Spring Assisted
- Tilted Seat for Reduced Hammer
- Low Cracking Pressures
- Positive Shut Off with Gravity Closure
- Low Maintenance Requirements
- Vertical or Horizontal Installation
- Wafer Pattern - Series "T"
- Lug Wafer Pattern - Series "F" or "L"
- ANSI B16.10 Face-to-Face - Series "X"
- Plastic Bodied Check Valve - Series "P"
Available in the following body patterns:
Severe Service
- Integral Stops on Flapper to Absorb Stress During Cycling
- Tilt Seat for Reduced Hammer
- Large Pin Diameter for Extra Strength
- Non-Spring Assisted
- 25% Cr. Duplex Stainless Steel Flapper Material for Maximum Strength
- Wafer Pattern - Series "T"
- Lug Wafer Pattern - Series "F" or "L"
- ANSI B16.10 Face-to-Face - Series "X"
Available in the following body patterns:
Extended Face-to-Face
- Longer Face-to-Face for Full Opening Flapper
- Increase Flow Capacity
- Installation Upstream or Downstream of Other Valves (except other wafer pattern valves)
- Wafer Pattern - Series "T"
- Lug Wafer Pattern - Series "F" or "L"
Available in the following body patterns: