The GWDRY Series Pilot Operated Piston High-Temperature Solenoid Valve (with nominal sizes spanning from DN15 to DN50) is a premium, heavy-duty automatic control valve engineered for modern industrial thermal networks, high-temperature gas transmission lines, complex liquid circulation loops, and high-severity thermal oil (heat transfer fluid) automation networks. Serving as a crucial isolation component within automated fluid loops, this series features advanced structural optimization designed to solve common industry issues such as carbon choking, mechanical jamming, and thermal deformation leaks. This series offers both threaded and flanged connection profiles, with models featuring suffixes "F" and "JF" custom-tailored for medium-to-high pressure industrial flanged pipelines.

The GWDRY series operates as a Normally Closed (NC) valve utilizing a fluid-assisted pilot-operated mechanism.

When the electromagnetic coil is de-energized, the internal plunger is forced downward by the return spring, completely sealing the central pilot orifice located at the geometric center of the main piston. Consequently, the upstream process fluid flows from the inlet side into the upper piston cavity via a specialized balancing throttling port. Because the pilot orifice is sealed, fluid pressure rapidly builds within the upper chamber until it reaches static equilibrium with the inlet line pressure. Leveraging the design geometry where the upper surface area of the piston is larger than the lower surface area, a downward net pressure differential is established. This high net fluid force, combined with the mechanical pre-load of the main return spring, presses the piston assembly firmly against the body seat, ensuring a zero-leakage tight shutoff.

When the electromagnetic coil receives an electrical current, it generates a high-density magnetic field. The resulting electromagnetic force overcomes the combination of internal spring resistance and plunger weight, pulling the plunger upward to open the central pilot orifice instantly. Because the cross-sectional flow area of the pilot orifice is significantly larger than that of the lateral balancing throttling port, the high-pressure fluid trapped in the upper piston chamber evacuates rapidly toward the low-pressure downstream side of the valve. This creates an immediate drop in upper chamber pressure. Consequently, the upstream process fluid pressure acting on the lower surface of the piston overcomes the residual upper chamber pressure, creating a strong upward net thrust. This force compresses the main spring and lifts the heavy piston assembly smoothly along the guided walls of the valve cavity, opening the valve completely. When the power is disconnected, the upper chamber pressure re-establishes within milliseconds, driving the piston down to complete the isolation cycle.

Product Image:GWDRY Piston Type High-Temperature Solenoid Valve

Pilot Piston Hard-Seating for Maximum Mechanical Lifespan: Conventional diaphragm-type high-temperature valves suffer from thermal vulcanization, hardening, micro-cracking, and sudden structural rupture when exposed to high-temperature oil or gas under frequent cycling. The GWDRY series replaces the flexible elastomer diaphragm with a precision-machined rigid metallic piston assembly. The piston rings mate tightly with the internal bore of the valve cavity and are supported by low-friction, high-temperature composite wear rings. This architecture provides excellent resistance against fluid scouring and mechanical abrasion, extending the fatigue lifecycle far beyond that of standard diaphragm alternatives.

Dual Material Configurations for Targeted Industrial Application: This series offers a choice between cast brass and SS304 stainless steel valve bodies. The investment cast brass configuration provides an economical, corrosion-resistant solution for commercial water heating, high-temperature air circulation, and standard utility boiler lines. The premium SS304 stainless steel body provides excellent resistance against pitting and chemical degradation, making it suitable for chemical thermal oil systems, pharmaceutical manufacturing, and food machinery where media purity and environmental durability are mandatory.

Medium-Assisted Throttling with High Flow Capacity: By leveraging the native energy of the process fluid to stroke the internal piston, even the largest DN50 valve can be actuated under 12 bar pressure using a low-power, energy-efficient electromagnetic coil. The internal flow channels are hydrodynamically modeled to eliminate sharp corners and stagnation zones, minimizing flow resistance and increasing the overall flow coefficient.

Universal Compatibility with Threaded and Flanged Options: To meet the requirements of international trade and worldwide engineering procurement, the GWDRY series is available with both threaded configurations and heavy-duty flanged designs (F/JF series). This choice allows for direct installation into international pipeline architectures without requiring external adaptors, eliminating potential leak paths and reducing on-site mechanical assembly costs.

Structure Diagram:GWDRY Piston Type High-Temperature Solenoid Valve

Specification Sheet

Outline Diagram:GWDRY Piston Type High-Temperature Solenoid Valve

Outline Dimension Table   （Unit:mm）