Gaoshan Valve — H42F-16Q Silent Check Valve

Model: H42F-16Q  |  Pressure: PN16  |  Connection: Flanged  |  DN Range: DN40–DN400  |  Type: Vertical Lift, Spring-Loaded

Core Strengths

Product Overview

The H42F-16Q silent check valve is a spring-loaded vertical lift check valve engineered for quiet, reliable backflow prevention in pressurized water, oil, and steam systems. Unlike conventional swing check valves that slam shut with audible impact, the H42F employs a guided vertical disc that closes smoothly against a precision-machined metal seat under calibrated spring force. The QT450-10 ductile iron body and bonnet provide exceptional structural strength, while the ZG2Cr13 stainless steel disc assembly resists corrosion and wear in demanding fluid environments. A high-quality 60Si2Mn silicon-manganese spring ensures consistent return force across thousands of operating cycles. Rated at PN16 with a maximum temperature of 200°C, the H42F covers DN40 through DN400 and is suitable for clean water, oil products, and steam service. The flanged end connections conform to standard flange drilling patterns for straightforward installation into existing pipelines.

Performance Specifications

Materials of Main Parts

Main Dimensions & Weights (PN16)

* L = Face-to-Face Length. All values are for reference only. Dimensions may vary slightly by manufacturing batch. Contact us for certified drawings.

Structure Drawing

Design & Manufacturing Standards

• Design Standard: GB/T 12236
• Face-to-Face Dimensions: GB/T 12221
• Flange Standards: GB/T 9113, JB/T 79, HG/T 20592
• Testing & Inspection: GB/T 13927, JB/T 9092
• Ductile Iron Material: QT450-10 per GB/T 1348
• Applicable International Standards: API 6D, BS 1868 (optional)

Installation & Maintenance Guidelines

• Vertical Installation Only: The H42F silent check valve must be installed in a vertical pipeline with flow direction upward. Horizontal installation is not supported as gravity will prevent proper disc sealing. Ensure the body flow arrow points upward.
• Pump Discharge Positioning: Install directly at the pump discharge outlet to protect the pump from reverse rotation and water hammer when the pump stops. Independent valve support is recommended for larger sizes (DN200 and above) to prevent flange stress.
• Flow Direction Verification: The valve body is permanently marked with a cast flow direction arrow. Install the valve so that fluid flows upward in the direction of the arrow. Reverse installation will prevent the disc from lifting and may damage the spring mechanism.
• Flange Bolting: Tighten flange bolts in a diagonal star pattern to ensure even gasket compression. Do not over-torque, as excessive stress on the ductile iron body may cause flange distortion. Follow standard flange torque tables for the bolt grade and gasket type in use.
• Spring Inspection: Periodically inspect the spring for fatigue, corrosion, or loss of free length. A weakened spring will delay disc closure and increase the risk of reverse flow. Replace the spring if the valve fails to close promptly after pump shutdown.
• Disc and Seat Maintenance: Check the metal disc and seat surfaces for scoring, pitting, or erosion during scheduled maintenance. Minor imperfections can be corrected by lapping. Replace the disc assembly if leakage exceeds the seal test acceptance criteria.
• High-Temperature Service: For steam service above 150°C, ensure adequate pipeline expansion compensation is provided to prevent thermal stress on the valve body. Allow the valve to cool before disassembly.

Application Fields