CAMTOP Pressure Relief Valve (PRV) — Shear Pin Safety Valve | 2″ & 3″ | 500–5,000 PSI

CAMTOP Pressure Relief Valve (PRV)

Shear Pin Safety Valve | 2″ & 3″ | 500 – 5,000 PSI | NPT Threaded | Mud Pump Protection

CAMTOP Pressure Relief Valve (PRV) is a critical safety protection device designed for high-pressure mud pump and manifold systems. The valve normally operates in a closed state and automatically opens when system pressure exceeds a preset threshold, safely discharging drilling fluid from the side outlet to prevent pipeline damage and catastrophic failure. The pressure setting is precisely controlled by selecting the correct shear pin diameter, allowing flexible and accurate pressure adjustment in the field.

Constructed with a hardened valve stem and a small piston area design, the CAMTOP PRV ensures reliable, repeatable opening and closing performance. The threaded valve cover enables easy installation and quick field reset, while the standardized NPT connections provide universal compatibility with all major pump brands. Available in 2″ and 3″ sizes, the CAMTOP PRV covers relief pressures from 500 PSI to 5,000 PSI, making it the ideal overpressure protection solution for drilling, well service, and cementing operations.

Figure 1. CAMTOP PRV Cross-Section — Internal stem, piston assembly, shear pin mechanism, and NPT threaded connections

Q: How does a CAMTOP shear pin pressure relief valve work?
A: The CAMTOP PRV operates by balancing mud pressure acting on the piston surface against the shear strength of the shear pin. When pipeline pressure exceeds the shear pin’s rated threshold, the upward thrust on the valve stem shears the pin, causing the valve to open instantly and discharge fluid through the side outlet. After pressure drops, the valve can be reset by installing a new shear pin and reassembling the threaded bonnet.

Q: What pressure range do CAMTOP PRVs cover?
A: CAMTOP PRVs are available in 2″ and 3″ sizes with relief pressure settings ranging from 500 PSI (34.5 Bar) to 5,000 PSI (344.7 Bar). The exact pressure is determined by the shear pin grade (color) and the number of pins installed (single or double). The complete pressure matrix is provided in the Technical Specifications table above.

Q: How do I select the correct shear pin for my application?
A: Select a shear pin grade based on your maximum allowable operating pressure. Choose a pin with a relief pressure approximately 10-15% above your normal operating pressure. For example, if your mud pump operates at 1,800 PSI, a #40 Green pin (2,000 PSI relief on a 2″PRV-21050 with 1 pin) would be appropriate. Always consult the pressure setting table before installation and ensure the pin grade matches the valve model and pin count.

Q: Can I use two shear pins for higher pressure settings?
A: Yes. The double-shear bonnet design allows installation of two identical shear pins in parallel. This doubles the relief pressure for the same pin grade. For example, two #30 Grey pins on a 2″PRV-21050 provide 3,000 PSI relief instead of 1,500 PSI with a single pin. Always ensure both pins are the same grade and properly seated before operation.

Q: What installation precautions should I follow?
A: Install the CAMTOP PRV vertically with the inlet connection at the bottom and the side outlet unobstructed. Ensure there is no back-pressure or flow restriction at the outlet port. Verify the correct shear pin grade and model match before installation. Always test the valve for proper sealing before putting it into service, and conduct regular inspections during operation to check for corrosion, wear, or leakage.

Q: Are CAMTOP PRVs compatible with other pump brands?
A: Yes. CAMTOP PRVs use standard NPT threaded connections (2″ and 3″) that are universally compatible with all major mud pump brands including National, Oilwell, Gardner-Denver, Emsco, and Ideco. The standardized design ensures direct replacement and interchangeability with OEM shear pin safety valves.

Q: What is the recommended maintenance schedule?
A: Inspect the PRV monthly during active drilling operations. Check for visible damage, corrosion, and leakage. Replace the stem cushion, piston kit, and O-ring every 500 operating hours or after any shear pin activation event. Replace the valve stem if surface hardness is reduced or if scoring is visible. Always keep a spare shear pin set and minor repair kit on-site for emergency replacement.

Q: What fluids are CAMTOP PRVs compatible with?
A: Standard CAMTOP PRVs with NBR seals are compatible with water-based drilling muds, oil-based drilling fluids, cement slurries, and completion fluids. For high-temperature applications above 82°C or for H₂S-containing sour gas service, contact CAMTOP for alternative seal material options (FKM, HNBR, or specialized compounds).

Q: How do I reset the valve after a shear pin activation?
A: After a pressure relief event, shut down the pump and depressurize the line. Remove the safety cover, unscrew the threaded bonnet, remove the sheared pin remnants, and inspect the stem and piston for damage. Replace any damaged components, install a new shear pin of the correct grade, reassemble the bonnet, and perform a seal test before returning to service.

Q: What is the lead time for CAMTOP PRV orders?
A: Standard 2″ and 3″ PRV models with common shear pin configurations are typically available from stock with 1-2 week lead time. Complete shear pin sets and repair kits are also stocked for immediate shipment. Custom configurations, high-temperature seal options, or large bulk orders may require 3-4 weeks. Contact CAMTOP sales for current availability and expedited delivery options.