Product Name: Internal Inlet Check Valve Assembly (Part No. 303401)

Description:
This component is a complete internal inlet check valve assembly for high-pressure waterjet intensifier pumps . It is a pre-assembled unit that controls the one-way flow of water entering the high-pressure cylinder from the low-pressure supply . The assembly typically includes the valve body, poppet, seat, spring, and all necessary sealing elements such as O-rings and backup rings. It is rated for continuous operation at 60,000 PSI (approximately 4,137 bar).

This assembly is designed as an upgrade from older check valve designs. Please note that if upgrading from the 301641 check valve assemblies to the 303401 assemblies, it is necessary to upgrade to the 303294 liquid displacers simultaneously. Failure to do so will result in damage to the pump .

Applications:

• Controls the intake flow of water into the high-pressure cylinder of the intensifier pump

• Prevents reverse flow when the intensifier switches direction during the compression stroke

• Suitable for ultra-high pressure waterjet systems operating at 60,000 PSI and above

• Compatible with OMAX and AccuStream waterjet intensifier pump assemblies

Features:

• Complete Assembly: Pre-assembled unit containing all internal components for drop-in replacement 

• Upgraded Design: Improved over earlier 301641 assemblies for enhanced performance and reliability 

• High-Pressure Rating: Engineered for continuous operation at 60,000+ PSI

• Corrosion-Resistant Construction: Manufactured from materials designed to withstand waterjet operating environments

• OEM Compatibility: Direct replacement for OMAX #303401 and AccuStream systems 

Maintenance:

Failure Diagnosis:

• Localized Heating: If a specific check valve assembly becomes noticeably hot during operation, it indicates internal leakage and requires inspection or replacement 

• No Pressure on One Side: If the intensifier pump builds no pressure when the piston moves in one direction, the corresponding inlet check valve may be damaged or worn 

• Uneven Cycling Speeds: If the piston moves faster in one direction than the other, a check valve assembly may be damaged 

• Pressure Drop: Inability to maintain rated cutting pressure may indicate worn check valve components

• External Leakage: Visible water weeping from the check valve body area indicates seal failure

Inspection and Replacement Procedures:

• Full Depressurization: Always fully depressurize the waterjet system and follow lockout/tagout procedures before removing or servicing the check valve assembly

• Complete Assembly Replacement: When check valve failure is detected, replace the entire assembly as a unit rather than attempting to rebuild individual components

• Seal Replacement: When reinstalling, always replace associated O-rings and seals to ensure leak-free operation

• Torque Compliance: Tighten retaining components to the specific torque values listed in the equipment service manual

• Clean Installation: Ensure the mounting cavity and mating surfaces are thoroughly cleaned before installing a new assembly

Important Compatibility Note:

• When upgrading from the older 301641 check valve assemblies to the new 303401 assemblies, you must also upgrade to the 303294 liquid displacers simultaneously. Failure to do so will result in pump damage .

Cross-Reference Information:

• OMAX #303401 

• AccuStream Check Valve Assembly 

• Also known as Internal Inlet Check Valve Assembly