Buried Composite Pipe Installation: Best Practices for Gas Stations

Proper installation of buried composite pipes is critical to achieving the 30+ year service life these systems are designed to deliver. Here are the best practices every installation team should follow.

Before You Dig: Planning and Preparation

Site survey: Map existing utilities, tank locations, and dispenser positions
Pipe routing: Plan the shortest practical routes to minimize connections
Material check: Inspect all pipes and fittings for shipping damage
Tool preparation: Ensure electrofusion welder is calibrated and pipe cutter is sharp

Installation Steps

Step 1: Trenching

Excavate trenches to the required depth (typically 600-1200mm). Ensure the trench bottom is smooth and free of sharp objects that could damage the pipe wall. Add a 100mm sand bedding layer.

Step 2: Pipe Preparation

Cut pipes square using a proper pipe cutter. Clean the joining ends with the manufacturer-recommended solvent. Do not use petroleum-based cleaners that can damage composite materials.

Step 3: Electrofusion Welding

Insert the pipe ends into the electrofusion coupler. Connect the welder and follow the manufacturer settings. Allow the joint to cool completely before moving.

Step 4: Leak Detection Installation

If using double-wall pipes, connect the interstitial monitoring lines to the leak detection system at this stage. Test the detection function before backfilling.

Step 5: Pressure Testing

Pressurize the completed pipe system to 1.5 times the working pressure. Hold for at least 30 minutes. Document pressure readings for compliance records.

Step 6: Backfilling

Backfill with sand or fine gravel in 200mm layers, compacting each layer. Place warning tape 300mm above the pipes.

WoHong Petrochemical Guidance

WoHong Petrochemical provides detailed installation manuals and on-site technical support for all our underground composite pipe systems.