Product ID: 20429338 – Plunger Retainer Nut / Piston Retaining Nut

Description:
This component is a plunger retainer nut, also known as a piston retaining nut or high-pressure cylinder piston retaining washer, designed for waterjet intensifier pumps . It is a precision-engineered fastening component used to securely connect and lock the ceramic plunger to the hydraulic piston within the intensifier assembly . The nut ensures a stable, vibration-resistant mechanical connection that maintains proper alignment and prevents loosening under the extreme cyclic forces of ultra-high-pressure operation .

This part is manufactured from corrosion-resistant stainless steel . This item has been discontinued as part of an antiquated assembly; the replacing part is item number SP05118716 .

Applications:

• Used in waterjet intensifier pumps to secure the ceramic plunger to the hydraulic piston assembly 

• Installed within the high-pressure cylinder section of the intensifier, functioning as a critical locking mechanism

• Suitable for ultra-high pressure waterjet systems operating at 40,000–90,000 PSI (approximately 2,800–6,200 bar) 

• Compatible with SL-I50 series intensifier pumps and other standard waterjet systems 

Features:

• Stainless Steel Construction: Manufactured from corrosion-resistant stainless steel for durability in harsh waterjet environments 

• Precision Threading: CNC-machined threads ensure a tight, secure fit and precise torque control for reliable fastening 

• Plunger Fixation: Primary function is to fix the ceramic plunger to the piston within the intensifier multiplier 

• High-Pressure Rating: Engineered to withstand continuous operation at ultra-high pressure without deformation or loosening 

• Vibration Resistance: Design ensures stable connections that maintain alignment and prevent loosening under cyclic loading

Maintenance:

• Critical Discontinuation Notice: This item (20429338) has been discontinued as part of an antiquated assembly. The direct replacement is item number SP05118716 . Do not attempt to source the original part; upgrade the entire assembly to use the replacement component

• Inspection During Overhaul: If the existing retainer nut is still in use, inspect for signs of thread damage, galling, cracking, or corrosion during routine pump maintenance

• Torque Compliance: When reinstalling, tighten to the specific torque value listed in the equipment service manual to ensure proper clamping force without damaging threads

• Thread Lubrication: Apply manufacturer-recommended anti-seize compound to threads during reassembly to prevent galling and ensure accurate torque application

• Full Depressurization: Always fully depressurize both the hydraulic system and the high-pressure water system before removing or installing the plunger retainer nut. Follow lockout/tagout procedures

• Replacement Criteria: Replace the retainer nut if threads are damaged, if cracking is detected, if the nut shows signs of deformation, or if the nut cannot maintain proper torque

• Cross-Reference Information: This part is also known as a piston retaining washer or high-pressure cylinder piston retaining nut for SL-I50 series intensifiers