When temperature, vacuum, permeation, or fire exposure rule out elastomers and PTFE, corrugated metal hose takes over. It's the only flexible connector that runs from cryogenic LNG to 1,200°F exhaust, holds absolute vacuum indefinitely, and cannot burn through. The trade-off is fatigue behavior — metal hose is flexible, not tireless — so application discipline matters.

Where Metal Hose Belongs

Steam and hot oil jumpers beyond rubber's range, thermal expansion legs on pumps and exhaust, cryogenic transfer (LN2, LNG, CO2), high-vacuum lines where permeation through polymer walls is unacceptable, fire-safe fuel connections, and gas service (see our metal hose collection). Semiconductor and lab facilities use it for process vacuum and gas pigtails for exactly the permeation reason.

Construction Choices

Annular corrugated hose in 316L is the standard: rings of corrugation give flexibility and vacuum capability, with single or double stainless braid carrying the pressure — unbraided corrugated hose has very low pressure ratings. Bronze hose suits plumbing and moderate duty economically. Interlocked (squarelock) hose is unbraided stripwound armor — excellent for exhaust routing and abrasion guard, but it is not gas-tight and carries no pressure. Alloy upgrades (321, Monel, Inconel) address chlorides, high temp, and sour service.

Fatigue Rules

Metal hose fails by corrugation cracking from cycling, and every rule protects against it: never torque the hose (use a union or lapped flange so the hose doesn't twist during install), respect minimum bend radius — static and dynamic radii differ — support long horizontal runs, keep vibration amplitude within rated limits, and never use metal hose to fix misalignment beyond its rated offset. Velocity resonance matters too: high-velocity gas flow across corrugations can sing a hose to failure; liners solve it.

Metal Expansion Joints

For pure axial/lateral thermal movement in piping, engineered metal bellows expansion joints — with limit rods and shipping bars per EJMA — replace hose. Provide design pressure, temperature, movements, and cycles, and the joint is engineered to match.

Fabricated to Your Spec

We fabricate braided metal hose assemblies with weld, flange, NPT, or union ends, and quote engineered expansion joints from your datasheet. Put size, alloy, ends, length, pressure, and temperature in the quote form at the top of this page — pricing and lead time in 1–2 business hours.