SAE 100R12 vs EN 856 4SP

Bend radius against pressure, at the same bore and the same four-spiral layup. At 3/8 inch our R12 is rated 28.0 MPa (280 bar) and bends to 125 mm, while our 4SP is rated 44.5 MPa (445 bar) and needs 180 mm. Everything else on the machine follows from which of those two numbers is tighter.

Upward is usually safe, downward is not. A 280 bar circuit that ran R12 can be re-hosed in 4SP because 4SP at 3/4 inch is rated 35.0 MPa, but the 4SP body needs 300 mm where R12 needed 240 mm, so the routing has to be re-checked. A 350 bar circuit that ran 4SP cannot be re-hosed in R12 at all.

The 4th code, 19 mm bore held 18.6 to 19.8 mm, is rated 28.0 MPa working, 4,061 psi, with 112.0 MPa (1,120 bar) minimum burst. Minimum bend radius is 240 mm and the body weighs 1.44 kg/m, so a 100 m coil is 144 kg.

Because that is how the range is built: all four rows from 10 mm to 19 mm carry 28.0 MPa, while the bend radius opens from 125 mm to 240 mm and the weight from 0.76 to 1.44 kg/m. 4SP does the opposite, holding 445 bar at 3/8 inch and dropping to 350 bar at 3/4 inch.

R12, because 280 bar already covers the circuit and its 125 mm bend radius at 3/8 inch fits the return routing. Fitting 4SP there buys 445 bar that the return line does not use, and costs 55 mm of bend radius.

4SP, and at 3/4 inch: 35.0 MPa (350 bar) with a 300 mm bend radius. R12 stops at 28.0 MPa (280 bar) across its whole range, so it cannot be used on that circuit at any bore.

Because the old routing was dimensioned around R12. A 3/8 inch run laid out to a 125 mm bend cannot take a 4SP body that needs 180 mm, so the fitter either forces the bend or lengthens the loop badly. Either way the wire at the ferrule works on every cycle, and the failure shows up just behind the nut.

At exactly the minimum there is no margin left for tolerance, temperature or a clamp that slipped. A 3/8 inch R12 held at 125 mm looks acceptable on the drawing and is already at the limit; run it at 150 mm and the same hose lasts.

YIBO, in Luohe, Henan, winds both classes on the same line, so a machine that needs R12 in four sizes and 4SP on two ram lines can ship as one order. R12 is published here from 10 mm to 19 mm bore, 3/8 inch to 3/4 inch.

Less wire, so less material: at 3/8 inch the bodies are 0.76 kg/m and 0.75 kg/m, effectively equal, but at 3/4 inch R12 is 1.44 kg/m against 1.63 kg/m for 4SP. Price also follows ends and quantity, so send bore, length and destination for a firm figure.