Selection
How to choose an air hose for a compressor and pneumatic tools
Pressure class, inner diameter, length, oil mist and temperature: what to check when choosing an air hose for a compressor and pneumatic tools.
Perrot couplings: how to determine the size
Why a Perrot coupling is sized by the pipe, not the hose, how male and female parts pair up, and how to read a code such as KMG 50 x 1½".
Perrot-type couplings are ball joint couplings that join pipes and hoses into a line that can be put together and taken apart quickly; the ball joint lets the line follow the ground. Their sizing differs from hose couplings, so here is how to determine the size you need.
The size is the outer diameter of the pipe
A Perrot coupling is sized by the outer diameter of the pipe it is made for, not by the inner diameter of a hose. Our range covers pipes from 50 to 305 mm: 50, 70, 89, 108, 133, 159, 216, 254 and 305 mm. To check an existing pipe, measure its outer diameter; if you only have a tape measure, measure the circumference and divide by 3.14.
Male and female parts
Every Perrot connection consists of a male part and a female part of the same size. Most items are made in both versions, so when you order, say which part you need — or which part is already on the other side of the connection.
Reading the codes
Perrot items are identified by codes, and our site search finds them. In a code, the first number is the coupling size — the pipe diameter — and the second is what is on the other end:
- KVS-K 70 x 65 — coupling size 70 with a barbed hose tail for a 65 mm hose;
- KMG 50 x 1½” — coupling size 50 with a 1½” thread;
- KMS 70×65/SUPRA — the suffix gives the material version.
Codes come in pairs, KV… and KM…: one for the male part and one for the female part of the same item.
Ends and materials
The other end of a Perrot coupling can be a barbed hose tail, a rolled tail, a thread, a flange or a cut flange, a short weld tube, or a weld-on part. There are three material versions: galvanized steel; OPTIMA — stainless steel; SUPRA — stainless and galvanized steel. Gaskets are available in universal, oil resistant, fuel resistant and heat resistant versions.
Fittings for the line
The range also includes bends of 30°, 45° and 90°, reducers, reversal pieces, T-pieces with and without a valve, end caps, couplings with a built-in valve, a suction valve with strainer, hydrant valves, stands and clamp supports. See all Perrot couplings.
Not sure what you have?
Send us the outer diameter of the pipe, a photo of the coupling or its code, and tell us whether you need the male or the female part. We also fit Perrot couplings with hose tails to hoses: see hose crimping and assembly. Contact us via the contacts page.
