Product ID: 20422243 – High Pressure Seal Assembly (Dynamic Seal for Intensifier Pump)

Description:
This component is a high-pressure dynamic seal assembly, also known as an HP seal kit or plunger seal assembly, designed for waterjet intensifier pumps . It is a critical consumable component that creates a leak-free, dynamic sealing interface between the reciprocating ceramic plunger and the high-pressure cylinder bore, preventing high-pressure water from bypassing the plunger during the compression stroke .

This seal assembly typically consists of multiple sealing elements including high-pressure seals (often 4 pieces), O-rings, backup rings, and anti-extrusion components made from materials such as rubber, plastic, and brass . It is precision-engineered to withstand continuous ultra-high pressure operation while allowing smooth reciprocating motion of the plunger .

This part is manufactured under the AccuStream brand (a division of Hypertherm) and is compatible with KMT waterjet systems . Alternative or cross-reference part numbers include 05149703, 1-12339, 104056, and 6104056 . The component has an approximate weight of 0.066–0.5 lbs (0.03–0.23 kg) depending on the specific kit configuration .

Applications:

• Used as the primary dynamic seal within the high-pressure cylinder of waterjet intensifier pumps

• Installed around the reciprocating ceramic plunger (0.875 inch diameter) to seal the high-pressure water chamber

• Suitable for ultra-high pressure waterjet systems operating up to 60,000–90,000 PSI (approximately 4,137–6,200 bar) 

• Compatible with KMT pump models including SL-V (15–60 HP), SL-VI (15–60 HP), SL-IV Plus (15–60 HP), and Neoline series 

• Also compatible with FLOW, OMAX, WSI, and other major waterjet intensifier systems 

Features:

• Dynamic Sealing Capability: Engineered for reciprocating motion applications, providing a leak-free seal between the plunger and cylinder bore while allowing smooth axial movement 

• High-Pressure Rating: Designed for continuous operation at 60,000–90,000 PSI (4,137–6,200 bar) without seal extrusion or failure 

• Multi-Material Construction: Manufactured from high-performance polyurethane (PU), PTFE composites, rubber, plastic, and brass components for optimal wear resistance and flexibility 

• Precision-Molded: CNC-molded and precision-finished to exact dimensional specifications for perfect fit and consistent performance 

• Dual-Lip or Multi-Element Design: Provides minimal friction, maximum sealing efficiency, and extended service life under extreme pressure cycling 

• Corrosion and Wear Resistant: Materials selected for resistance to water, hydraulic fluids, and abrasive contaminants in waterjet environments

• Standard Plunger Compatibility: Designed for systems with 0.875 inch (7/8") diameter plungers 

• OEM Quality: Direct replacement for KMT AccuStream original equipment, maintaining factory specifications 

Maintenance:

• Critical Wear Component: The HP seal assembly is a primary consumable part that requires periodic replacement as its performance degrades due to friction, pressure cycling, and normal wear 

• Performance Monitoring Indicators: Replace the seal assembly when the following symptoms appear:

• Drop in cutting pressure

• Increased pump cycling frequency

• Visible water dripping from the pump's weep or drain hole

• Water contamination of the hydraulic oil

• Inability to maintain rated cutting pressure 

• Preventive Replacement Schedule: It is recommended to replace the HP seal assembly as part of scheduled preventive maintenance (based on operating hours) rather than waiting for failure to avoid unplanned downtime

• Inspection During Replacement: When replacing seals, thoroughly inspect the ceramic plunger surface and the high-pressure cylinder bore for scoring, pitting, scratching, or uneven wear. A damaged plunger or cylinder will rapidly destroy a new seal assembly

• Proper Lubrication: During installation, lubricate the new seals generously with manufacturer-recommended high-pressure grease or assembly lubricant to prevent dry startup and reduce initial friction

• Surface Preparation: Thoroughly clean the cylinder bore, plunger surface, and seal grooves using a soft cloth and low-pressure water before installing new seals. Remove all debris, old seal residue, and mineral deposits. Do not use abrasive tools that could scratch sealing surfaces

• Use Proper Installation Tools: Use manufacturer-specified seal removal and installation tools to avoid scratching the cylinder bore or damaging the new seals during the procedure

• Complete Kit Replacement: Replace all seals in the kit as a complete set. Do not reuse individual seals from an old assembly or mix old and new components

• Full Depressurization (Critical): Always fully depressurize both the hydraulic system and the high-pressure water system before removing or servicing the seal assembly. Follow lockout/tagout procedures to prevent severe injury from high-pressure water release

• Torque Compliance: When reinstalling cylinder components, tighten all retaining nuts and hardware to the specific torque values listed in the equipment service manual to ensure proper seal compression and alignment

• Water Quality Impact: Poor water quality (contaminants, hardness, improper filtration) accelerates seal wear. If seals require replacement too frequently, investigate and improve water filtration/treatment systems

• Storage: Store spare seal assemblies in a clean, dry environment in sealed protective packaging away from direct sunlight, ozone, heat, and chemicals to prevent material degradation before use

• Cross-Reference Kits: This seal assembly may be available as part of larger intensifier rebuild kits or as a standalone component