KC nipples and shank couplings: the plain hose end, and how to make it hold

The simplest hose end there is has no moving parts: a tail with serrations that grips the inside of the hose, and on the other end a thread or a flange. KC nipples, shank couplings, pin-lug couplings and hose menders are all variations on it. They are cheap, they are everywhere, and they are only as good as what is clamped around the hose — which is the part that most often goes on as an afterthought.

/01KC nipples.

A KC nipple is a combination nipple — serrated tail one end, connection the other. Our range runs from a standard KC nipple and a grooved KC nipple (1/2" to 12", carbon steel, 304 or 316 stainless) to a heavy-duty KC nipple with a thicker SCH40 wall and a longer tail (2" to 12", NPT or BSPT, rated 300 psi). Heavy-duty versions also come with a welded Class 150 flange, as a fixed flange or a turnback flange.

/02The clamp is the rating.

A nipple pushed into a hose and held by a worm-drive band will hold low pressure on a soft hose and not much else. The serrations grip only as hard as the hose is squeezed onto them, and a band applies that squeeze along a narrow line. For anything that matters, use a clamp made for the job: an interlocking or double-bolt clamp sized to the hose outside diameter, a swaged ferrule for KC and cam-lock shanks (1/2" to 6"), or a crimped sleeve (1" to 8"). Each of those spreads the grip along the tail, which is what the serrations were designed for.

/03Shank couplings and pin-lug couplings.

A shank coupling pairs a male and a female nipple into a threaded union, so a hose can be broken without unclamping it. Our steel long-shank nipples (male, female and complete sets, 1/2" to 2") suit heavier transfer lines, where the long shank gives more grip in the hose; brass short-shank nipples (1/2" to 3/4" sizes) suit lighter service. A zinc-plated steel male NPT × hose-barb nipple covers the small sizes, from 1/8" × 1/4" up to 1" × 1". Sealfast publishes no working pressure for any of them, so the clamp and the hose set the limit — ask us to confirm one for your duty.

Pin-lug couplings are the water-service version: an aluminium shank with a brass nut carrying pin lugs for a spanner, 1-1/2" to 6", with a rubber washer in the nut; Sealfast publishes no working pressure for them. They are made to be tightened and loosened often, on irrigation and wash-down lines rather than pressure transfer.

/04Menders: a repair, labelled as one.

A hose mender is a tube with a serrated tail at each end, used to join two lengths of the same hose after a cut or a burst. Our brass menders run from 1/8" to 3/4" for light hose, and steel and stainless menders on the KC shelf from 1/2" to 12". A mender restores flow, not the hose's original rating — the joint is limited by its two clamps, and the hose either side is the same age as the part that failed.