Bulk material and sandblast hose: abrasion, static and the coupling that takes the blast

Most hoses fail from the outside — abrasion, sun, a rub point on a frame. Abrasive-duty hose fails from the inside. Sand, cement, fly ash, grain and blasting grit scour the tube with every metre they travel, and they scour hardest wherever the hose bends. Choosing a hose for that duty is mostly choosing the tube, and then making sure the static the flow generates has somewhere to go.

/01The tube does the work.

Our bulk material suction and delivery hose (A361) is built for dry and slurried abrasives: a black anti-static natural rubber tube — natural rubber being the classic compound for resisting sliding abrasion — over high-tensile textile plies, a steel helix for suction and anti-static wires, under an abrasion, weather and ozone resistant cover. It is rated 10 bar with a 30 bar burst (SF 3:1), −40 to +70 °C, in 3" and 4". For lighter slurries, and where some chemical resistance is wanted, the MDSE chemical and abrasion PVC hose (PREMFLEX) runs from 1-1/2" to 6" at 3 to 5 bar, −10 to +55 °C.

/02Static, and why it matters with powders.

Dry powders and grit sliding along a hose wall build an electrostatic charge, and in a dusty atmosphere a discharge can ignite the dust or simply give the operator a heavy shock. That is why A361 has both an anti-static tube and anti-static wires. As with any anti-static hose, the path only works if the couplings are bonded to the wires and the couplings are earthed — check continuity when the assembly is made and at every inspection.

/03Bends are where it wears.

Abrasive particles travel in straight lines and strike the outside of every bend, so that is where the tube wears through first. Route abrasive hose in long, gentle curves rather than tight ones, support it so it does not sag into a kink, and where a bend cannot be avoided, plan to rotate the hose a quarter turn at intervals so the wear is spread around the tube. A361's minimum bend radius is listed at 380 mm on 3" and 550 mm on 4"; staying well above it on abrasive duty buys life.

/04Sandblast couplings and nozzle holders.

Blasting hose has its own small family of ends. Our sandblast range covers aluminium hose ends with crowfoot faces (3/4" to 1-1/2"), NPSH-threaded nozzle holders (3/4" to 1-1/2"), and nylon hose couplers, female thread adapters and nozzle holders in 1-1/4" and 1-1/2", in yellow or red. Sealfast's nozzle holders are NPSH-threaded (ASME B1.20.7), and only one part has a published rating: Sealfast's aluminium female NPT crowfoot end, at 110 psi. Confirm the rest for your blast pressure — and the hose still sets the limit.