EN ISO 4144 covers the types, pressure-temperature ratings, materials and minimum dimensions of steam, air, gas, water and oil ordinary applications.
ISO ( International Organization for Standardization ) is a worldwide federation of national standards bodies. They developed this standard for stainless steel fittings for threaded connections in accordance with ISO 7-1.
Stainless Steel Fittings ISO 4144
This standard recommend use austenitic stainless steel having the proof stress at least equal to that of steel TS 47 specified in ISO 2604-2, and its equivalent material standards include ASTM A182. But ASTM A182 has so many grades, which one is the material of EN ISO 4144 Threaded Fittings.
The most commonly used Stainless Steel Grades are SS316 and SS304.
Stainless Steel 316L is also a kind of 316 stainless steel with less carbon content of 0.3% max. The primary reason for using an L grade stainless steel is that this will reduce the tendency of the material to crack after welding.
Stainless Steel BSP Fittings 316L
EN ISO 4144 Threaded Fittings are available in BSP types. That shall be in accordance with ISO 7-1 (BSP thread), external and internal threads are tapered 1:16 (BSPT), but internal threads may be parallel (BSPP). Thread ends should be chambered.
BSPP (British Standard Parallel Pipe) is most popular in the UK, Europe, Asia, Australia, New Zealand and South Africa. It is sealed by the bonded seal ring, no thread sealant is needed to form the seal. The thread angle is 55 degree.
BSP Pipe Fittings Pressure
| Temperature℃ | Non-shock Maximum Working Pressure Bar |
| -20 to 40 | 20 |
| 100 | 16.5 |
| 150 | 15 |
| 200 | 15 |
| 220 | 13.5 |
For Forged ASME B16.11 Fittings, 3000# Threaded Fittings seem like the most common type, but BSP pipe fittings EN ISO 4144 have a pressure rating below 3000LB.
Types of EN ISO 4144 Fittings
This standard includes a variety of threaded fittings, such as:
- Elbows (45° and 90°)
- Tees and Crosses
- Couplings and Reducers
- Hex Nipples and Bushings
- Caps and Plugs
- Unions
All fittings are supplied with BSP (British Standard Pipe) threads in accordance with ISO 7-1, ensuring compatibility and easy installation.
| Table 1—Types of fittings and their symbols | |||
| Diagram | Type | Symbol | Figure |
 | Elbows, equal and reducing | E1 and E2 | 2 and 3 |
 | 45°elbows | E3 | 4 |
 | Male and female elbows | E4 | 5 |
 | Tees,equal and reducing | T1 and T2 | 2 and 3 |
 | Crosses | X1 | 2 |
 | Half sockets | S1 | 6 |
 | Sockets, equal and reducing | S2 and S3 | 7 and 8 |
 | Reducing bushes | B1 | 9 |
 | Hexagon nipples, equal and reducing | N1 and N2 | 10 and 11 |
 | Caps | C1 | 12 |
 | Plugs | P1 and P2 | 13 |
 | Unions | U1,U2,U3 U4,U5,U6 | 14 |
ASME B16.11 and ISO 4144
Both standard of the size range are 1/8 to 4 inch (DN 6 -100). The difference as following.
Manufacture Technique
Types
Material Range
Thread Type
Pressure Rating
If you have any requirements of forged steel fittings and flanges, whatever ASME B16.11 & BS3799 or EN ISO 4144, we are your first choice.