Anti‑permeation HDPE‑EVOH double containment pipe is purpose‑built for underground fuel piping systems of filling stations. Produced via multi‑layer co‑extrusion process, the inner wall incorporates an EVOH high‑barrier layer to suppress hydrocarbon permeation. The double‑wall containment structure forms a pipe‑in‑pipe safety system. The annular interstitial space between inner product pipe and outer containment pipe can connect with leak monitoring devices for continuous leakage surveillance. In case of inner pipe failure, the outer HDPE pipe can hold back leaked fuel, preventing petroleum from contaminating surrounding soil and groundwater.
Based on high‑density polyethylene material, the composite pipe possesses outstanding chemical compatibility with gasoline, diesel, ethanol‑mixed fuels and biodiesel. Different from buried steel pipelines, it is free from electrochemical corrosion, securing long‑term service life under underground burial environment. Conductive version is optional for static dissipation, eliminating static charge accumulation caused by high‑speed fuel flow inside pipelines and lowering fire‑hazards at filling sites.
Matching PE electrofusion fittings are applied for pipeline connection. Electrofusion welding realizes molecular fusion between pipe and fitting, delivering permanent sealed joints and cutting down potential leakage points. The pipe is available in continuous coil and straight pipe options. Coiled pipe reduces on‑site welding quantity, simplifies laying procedure and shortens construction cycle. It fits for brand‑new filling station construction, as well as retrofitting and expansion of old fuel stations.
The piping system retains stable mechanical property under soil overburden pressure and ground vehicle load. Its burst pressure exceeds regular working pressure substantially to ensure operational security. A full range of auxiliary components including tees, elbows, reducers and end caps can be supplied to construct complete underground piping networks, applicable for fill lines, suction lines and VRU vapor recovery pipelines.
Thanks to the EVOH barrier layer, fuel vapor escape loss is significantly reduced to meet strict environmental compliance standards. Multiple sizes can be selected according to flow capacity and site layout requirements. Featuring high safety level and low later‑stage maintenance workload, this double containment pipe offers dependable underground fuel transmission solution for modern filling station projects.