Product Name: Sealing Head Assembly / Check Valve Body – P/N 20458908

Description:
The Sealing Head Assembly (20458908) is a complete high‑pressure check valve assembly for the intensifier pump in a waterjet cutting system . Often referred to interchangeably as the check valve body in parts diagrams, it serves as the central housing that directs and controls the one‑way flow of water into and out of the high‑pressure cylinder .

This assembly is the core component that converts the reciprocating motion of the plunger into a unidirectional, ultra‑high‑pressure water stream, ensuring that water is drawn in during the intake stroke and forced out to the cutting head without backflow . It is rated for continuous operation at 60,000–94,000 PSI (approximately 4,137–6,480 bar).

Complete Assembly Components

According to manufacturer documentation, the Sealing Head Assembly includes the following parts (Table 12‑3) :

A complete repair kit (20458830) is available, which includes items 3, 4, 5, 6, 8, 9 and 10 for a full overhaul .

Applications:

• Serves as the main check valve housing at the high‑pressure end of waterjet intensifier pumps

• Controls water intake (inlet side) and pressurized water discharge (outlet side) during intensifier cycling

• Used during scheduled preventive maintenance or when check valve failure symptoms appear

• Compatible with 60k‑94k waterjet systems (KMT, H2O Jet, AccuStream, Flow)

Features:

• Complete Assembly – drop‑in replacement for the check valve body section of the intensifier

• Dual Check Valve Design – integrates both inlet and outlet check valves in one housing

• Precision‑Machined Stainless Steel – high‑strength, corrosion‑resistant construction for extreme pressure cycling

• Serviceable – internal wear components (poppets, seats, springs, O‑rings) can be replaced without discarding the entire body

Maintenance:

Failure Diagnosis (When to Inspect/Service):

• Check Valve Body Hotter Than Normal – a specific sealing head running hot indicates internal leakage 

• Pressure Drop – inability to maintain rated cutting pressure suggests worn internal components

• External Water Leakage – water weeping from the sealing head area indicates seal or O‑ring failure

• Erratic Intensifier Cycling – irregular piston movement may point to a faulty inlet or outlet check valve

• Overheating Intensifier Components – excessive heat in the high‑pressure cylinder area can be a sign of check valve leakage 

• Scheduled Preventive Maintenance – manufacturers recommend servicing check valves every 1,000‑1,500 operating hours

Service Procedures:

• Full Depressurization (Critical) – before any maintenance, lock out the main electrical disconnect, fully depressurize the high‑pressure water system and the hydraulic system, and follow lockout/tagout procedures

• Complete Overhaul or Kit Replacement – use the Sealing Head Repair Kit (20458830) which includes all necessary wear components for a full rebuild

• Inspect Internal Passages – when disassembled, thoroughly clean and inspect the body bore and sealing surfaces for pitting, scoring, or erosion

• Lapping of Surfaces – minor surface imperfections on the cone ring contact surface or inlet poppet seat can be refinished using fine grit (e.g., 400‑600 grit) lapping paper on a flat glass plate, using a figure‑eight or radial motion

• Lubrication – apply high‑pressure grease to O‑rings and seals during reassembly to prevent dry start‑up and ensure proper seating

• Torque Compliance – when reinstalling, tighten all retaining components (gland, screws) to the torque values specified in the equipment service manual

• Upgrade Note – newer check valve designs (e.g., H2O Jet style) are smoother and faster than older designs, protect downstream components from hydraulic shock, and can be retrofitted into existing check valve bodies without modification 

Cross‑Reference Information:

• H2O Jet / KMT / AccuStream #: 20458908

• Repair Kit: 20458830 (includes items 3, 4, 5, 6, 8, 9, 10)

• Body only: 20458098 (Item 1)