Product Name: Valve Stem / Flat Poppet Valve Needle (Part No. 20435636)

Description:
This component is a high-precision valve stem, often referred to as a flat poppet valve needle, designed specifically for the pneumatic on/off valve assembly (water switch) in ultra-high pressure waterjet cutting systems .

Operating as the central moving element within the valve body, its primary function is to physically open or close the high-pressure water flow path. The valve stem works in conjunction with a valve seat (such as P/N 10178697) and a dynamic seal assembly (such as P/N 20428052) . When the pneumatic actuator is engaged, it moves this stem to open the valve; when the air supply is vented or the spring returns, the stem reseats against the valve body to stop the water flow .

Applications:

• Used as the primary actuating element in the pneumatic on/off valve (water switch) of waterjet intensifier pumps.

• Directly responsible for the precise start and stop of the high-pressure cutting jet.

• Compatible with KMT, AccuStream, Flow, OMAX, and WSI waterjet systems .

• Suitable for ultra-high pressure systems operating at 60,000 PSI (approximately 4,137 bar).

Features:

• Ultra-High Pressure Tolerance: Engineered to withstand extreme mechanical stress and repetitive impact within the valve body at 60,000+ PSI .

• Precision Flat Poppet Design: Features a precision-ground flat sealing surface (poppet) that ensures positive, leak-tight shut-off against the valve seat .

• High-Strength Material: Manufactured from hardened stainless steel or carbide to provide superior wear resistance, corrosion protection, and dimensional stability .

• Critical Wear Component: Considered a consumable high-wear part; its condition directly affects the responsiveness of the water switch and the prevention of water drips from the cutting head.

• Direct Replacement: Interchangeable with OEM part numbers including KMT 20435636 and WSI VL20435636 .

Maintenance:

When to Replace (Failure Diagnosis)

• Water Leakage: If water drips continuously from the mixing tube when the cutting jet is turned "OFF", the valve stem is likely worn and cannot seal against the seat.

• Sluggish Operation: If the water jet fails to start immediately or cuts off slowly, the valve stem may be sticking or worn.

• Visible Wear: During disassembly of the water switch, inspect the polished tip (poppet) of the stem for pitting, erosion, uneven wear, or a visible "ring" where it contacts the seat. Even minor surface damage warrants immediate replacement.

Replacement Guidelines

• Full Depressurization (Critical): Before any maintenance, ensure the waterjet system is fully depressurized (hydraulic and HP water) and the air supply is locked out.

• Seat Matching: When replacing the valve stem, it is highly recommended to replace the corresponding valve seat (P/N 10178697) simultaneously. Reusing a worn seat with a new stem will prevent a proper seal .

• Kit Replacement: This part is often included in complete On/Off Valve Repair Kits (e.g., P/N VL2010), which also contain the seat, seals (20428052), O-rings, and backup rings for a comprehensive overhaul .

• Lubrication: Apply a thin film of high-pressure thread lubricant or O-ring grease to the stem and new seals during installation to prevent dry start-up and pinching.

• Torque Compliance: When reassembling the valve, tighten the pneumatic actuator and gland nut to the specific torque values listed in the equipment service manual to ensure proper alignment and compression.