FAQ's

This page answers common questions about electrofusion and molded butt fusion in HDPE piping systems, including how these processes work, where they are used, and key considerations for installation, performance, and field practices across water, gas, and industrial applications.

 
What is Electrofusion?
Electrofusion is a welding process that involves joining HDPE (high-density polyethylene) pipes and electrofusion fittings by melting the material at their interface using electrical energy. This creates a strong, homogenous fusion joint, bonding at the molecular level. The completed fusion is stronger than the pipe itself.

For more information, refer to PE100+ Association as a resource.
How does the electrofusion process work?
Electrofusion involves the use of a specialized high-density polyethylene (HDPE) fitting with an embedded heating element. Before the fusion begins, the fitting is restrained to the outer wall of the polyethylene pipe. The fusion process is controlled by a 24-digit barcode (the barcode is an international standard for electrofusion) found on the exterior of each fitting. Our Strongbridge electrofusion processor will scan the barcode and perform the fusion process according to the parameters set forth by the barcode. The completed fusion will be stronger than the pipe itself.

For more information, refer to Plastics Pipe Institute as a resource.
What are the advantages of using electrofusion HDPE fittings?
Electrofusion HDPE fittings are engineered for extreme durability and offer several benefits, including your best choice for a leak-free system, chemical resistance, impact resistance at low temperatures, and resistance to corrosion and abrasion.

EF fittings are also lightweight and offer easy installation, they can be suitable for a variety of media, including water, liquids, gases, and slurries. Strongbridge offers the largest size and pressure-class range of electrofusion fittings available. As the originator of large-diameter electrofusion couplers and saddles, we’ll custom design and manufacture specific to your project needs

Our electrofusion fittings are made with current PE100 resin in our ISO 9001 facility and meet international and domestic standards, including ASTM, AWWA, NSF, and FM Approvals.
What resin are your electrofusion fittings and molded fittings manufactured with?
Our Strongbridge HDPE electrofusion fittings and molded fittings are manufactured using high-density polyethylene (HDPE) 4710 / PE100 virgin resin.
Where do I send quote requests or purchase orders?
Send quote requests and purchase orders to sales@strongbridge.us.
Do you offer electrofusion training?
Yes.

Strongbridge provides in-person, hands-on electrofusion training and certification by a certified electrofusion instructor covering small through large diameter fittings. Training ensures proper preparation, tooling usage, and installation procedures are followed in the field.
What is the difference between butt fusion and electrofusion fittings?
Butt fusion fittings are SDR-specific and must match the pipe SDR. Electrofusion fittings are fusible to a range of SDRs listed on the fitting barcode.
Is SDR/DR important when selecting an electrofusion coupler?
Yes.

Each coupler is engineered for fusion to a defined SDR range. Using an electrofusion coupler on an SDR of pipe that is not intended for can result in insufficient heat or excessive melt, which can lead to joint failure. Always verify the SDR of the pipe falls within the SDR fusibility range listed on the fitting barcode.
Can electrofusion couplers be used with molded butt fusion fittings?
Yes.

Strongbridge molded butt fusion fittings can be joined by either butt fusion or electrofusion. When installed correctly, both methods produce a fully fused joint that is as strong as the pipe or fitting material.
Are electrofusion joints pressure-rated the same as the pipe?
Yes, when installed correctly.

A proper electrofusion joint forms a homogeneous bond intended to meet the system pressure rating. Joint performance depends on correct preparation, clamping, fusion, and cooling. Please reference the max operating pressure of the fitting and note that the max operating pressure of a line can be no more than the max operating pressure of the “weakest joint” on the line.
How should electrofusion fittings be stored?
Store fittings indoors in their original packaging. Protect them from dirt, moisture, and UV exposure. Remove packaging only at the time of installation to keep fusion surfaces clean.
What tools are required for electrofusion installation?
At minimum: measuring tools, marker, pipe cutters, approved peeling tools, 90%+ isopropyl alcohol, alignment or re-rounding clamps, electrofusion processor, and proper generator or power supply.
Can sandpaper or emery cloth be used to prepare the pipe?
No.

Abrasives do not remove oxidation correctly and can contaminate the surface. Only approved peeling tools designed for electrofusion preparation should be used.
How much pipe surface must be removed during peeling?
Remove a minimum of 0.007 in (0.18 mm) of material to eliminate the oxidized layer and expose the clean pipe surface required for fusion.
What should be used to clean the pipe before fusion?
Use clean water for initial washing and 90% or greater isopropyl alcohol for final cleaning. Do not use denatured alcohol or cleaners with additives.
Can electrofusion be performed if water is present?
No.

Fusion surfaces must be dry. Flowing or standing water can contaminate the joint and cause failure.
Are clamps required during fusion?
Yes.

All electrofusion fittings must be clamped to maintain alignment and prevent movement during fusion and cooling.
Why are re-rounding clamps sometimes required?
HDPE pipe can become oval during storage or burial. Ovality creates gaps between the pipe and fitting. Re-rounding clamps restore the correct diameter and ensure full contact before fusion.
When can clamps be removed or pressure testing begin?
After the full cooling time has elapsed. Do not move, backfill, or pressure test the fitting before cooling is complete.
Can electrofusion saddles or tapping tees be installed at any angle?
Yes.

Saddles and tapping tees may be fused at any position around the pipe circumference when the pipe is properly prepared, peeled, clamped, and braced.
Can valves or assemblies be attached to the outlet before fusion?
No.

Attach components only after fusion and cooling. Added weight during fusion can cause movement and result in a failed joint.
How do I check for gaps under a saddle?
Use a metal gap gauge up to 0.012 in (0.30 mm). If the gauge fits between the saddle base and pipe, reduce ovality with re-rounding clamps before fusion.
What are electrofusion flex restraints used for?
Flex restraints are commonly used as thrust-restraint anchors and as support tooling for large-diameter coupler installations.
Do large diameter saddles require special tooling?
Yes.

Saddles with 12-inch and larger outlets require the use of our specialized tooling, known as our large-outlet saddle tool, and distributor partner-trained and certified fusion technicians.
What tooling is recommended for large diameter couplers?
Recommended equipment includes re-round clamps, an approved electrofusion processor, coupler pullers, and flexible restraints.
Is the electrofusion processor waterproof?
No.

Processors are water-resistant only and should not be submerged or used in heavy moisture conditions.
Can I use a welding generator to power the processor?
No.

Use a properly sized generator or inverter that meets processor requirements. Welding generators are not recommended.
Can fittings be re-fused?
Only in cases of power interruption. If the processor faults for other reasons, the fitting should be removed or abandoned.
Can HDPE electrofusion systems be pneumatically tested with compressed air?
No.

Compressed air testing of HDPE pressure piping is prohibited for safety reasons.