Product Name: Collimation Tube / Focusing Tube (Part No. WJ070068/593)

Description:
This component is a collimation tube, also known as a focusing tube or mixing tube, specifically designed for high-pressure abrasive waterjet cutting systems . It is a precision-machined cylindrical component manufactured from ultra-hard, wear-resistant materials such as tungsten carbide or advanced composite carbides . The tube is installed in the cutting head assembly downstream of the mixing chamber, where it serves as the final exit point for the abrasive-laden waterjet .

Inside the collimation tube, the high-velocity waterjet and abrasive particles are accelerated and focused into a coherent cutting stream. The internal diameter (ID) of the tube is critical, as it determines the kerf width and cutting precision; standard sizes typically range from 0.020 inches (0.5 mm) to 0.060 inches (1.5 mm) . This component is a high-wear consumable, as the inner bore gradually erodes over time due to the abrasive action of garnet particles .

This specific part number (WJ070068/593) is an OEM replacement for BHDT/H2O Jet waterjet systems and works in conjunction with the orifice, mixing chamber, and valve body components.

Applications:

• Serves as the final focusing element for the abrasive waterjet, directing the cutting stream onto the workpiece

• Accelerates the water-abrasive mixture to optimal cutting velocity (approximately 900-1000 m/sec) 

• Defines the kerf width and cutting precision for the waterjet system

• Installed in the cutting head assembly of abrasive waterjet cutting machines

• Used during scheduled maintenance, performance restoration, or when cutting quality degrades

• Compatible with BHDT/H2O Jet waterjet cutting systems

Features:

• Ultra-Hard Material Construction: Manufactured from tungsten carbide or proprietary composite carbide (e.g., ROCTEC™), providing exceptional wear resistance and extended service life 

• Precision Inner Diameter: Manufactured to exact specifications; common diameters include 0.020", 0.030", 0.040", and 0.060" to match different orifice sizes and cutting applications 

• Optimized Length: Engineered lengths (typically 51mm to 138mm) affect jet coherence; longer tubes produce more coherent jets but experience increased wall friction 

• Critical Consumable Component: As a high-wear part, the collimation tube requires periodic replacement; its lifespan depends on abrasive type, flow rate, and operating pressure 

• 1:3 Diameter Ratio Rule: For optimal cutting performance, the collimation tube inner diameter should be approximately three times the water orifice diameter (e.g., 0.010" orifice with 0.030" tube)

• OEM Compatibility: Direct replacement for BHDT/H2O Jet waterjet systems

Maintenance:

Failure Diagnosis (When to Replace):

• Reduced Cutting Performance: Noticeable decrease in cutting speed, rougher edge finish, or increased taper indicates bore wear 

• Asymmetric Wear: Uneven wear around the tube outlet circumference indicates misalignment between the water orifice and collimation tube 

• Visible Bore Damage: Inspect the exit orifice for ovality, flaring, or visible bore enlargement using a magnifying glass or microscope

• Clogged Tube: Complete blockage of the tube often results from wet or contaminated garnet abrasive 

• Scheduled Preventive Replacement: Replace based on operating hours; advanced composite tubes may offer 20-30 times longer life than standard tungsten carbide 

Inspection and Replacement Guidelines:

• Regular Rotation Practice: Index (rotate) the collimation tube by 1/4 turn every 10-12 operating hours to distribute wear evenly around the circumference and extend service life 

• Orifice-to-Tube Ratio (Critical): Maintain a 1:3 diameter ratio between the water orifice and collimation tube. A ratio that is too large or too small will result in rapid consumable wear 

• Alignment Check: Ensure perfect coaxial alignment between the water orifice and collimation tube. Misalignment causes asymmetric bore wear, poor cut quality, and significantly reduced tube life 

• Handling Caution: The collimation tube is extremely hard but brittle; handle carefully to avoid chipping, cracking, or impact damage during installation 

• Full Depressurization (Critical): Before any maintenance, fully depressurize the waterjet system and follow lockout/tagout procedures

• Clean Installation: Thoroughly clean the mixing chamber and nozzle body before installing a new tube to remove debris that could cause misalignment

• Torque Compliance: When reinstalling the retaining nut, tighten to the specific torque value listed in the equipment service manual; over-tightening may crack the tube

• Water Quality Impact: Poor water quality with contaminants accelerates tube wear; maintain proper water filtration to maximize component life

• Abrasive Quality: Use clean, dry garnet abrasive; wet or contaminated abrasive can cause clogging, accelerated wear, and water backflow 

• Storage: Store spare collimation tubes in a clean, dry, protective environment to prevent pre-service damage to the delicate inner bore

Cross-Reference Information:

• BHDT/H2O Jet #: WJ070068/593

• Also known as: Focusing Tube, Mixing Tube, Abrasive Nozzle, Waterjet Nozzle

• Component of BHDT/H2O Jet waterjet cutting systems

• Compatible with standard waterjet cutting head assemblies