ASTM A420 WPL3 EN P355NL1 · 1.0566 −101°C Charpy

ASTM A420 WPL3 Pipe Fittings

Low-temperature carbon steel buttweld pipe fittings tested to −101°C. Used in LNG satellite stations, ethylene plants, cold gas service, and cryogenic storage piping where sub-zero Charpy toughness is mandatory.

Chemical Composition — ASTM A420 WPL3

Element	WPL3 Max %
Carbon (C)	0.20
Manganese (Mn)	0.90–1.60
Silicon (Si)	0.15–0.40
Phosphorus (P)	0.025
Sulphur (S)	0.025
Nickel (Ni)	3.18–3.82
Carbon Equivalent (CE)	≤0.43

Nickel addition (3.2–3.8%) is the key element providing sub-zero toughness in WPL3 — same principle as 3.5Ni steel used in LNG tankage.

Mechanical Properties

Property	WPL3
Tensile Strength (min)	450 MPa (65 ksi)
Yield Strength (min)	275 MPa (40 ksi)
Elongation (min)	22%
Charpy Test Temperature	−101°C (−150°F)
Charpy Energy (avg)	27 J (20 ft·lb)
Charpy Energy (min individual)	20 J (15 ft·lb)
Heat Treatment	Normalised or Q+T

WPL3 vs WPL6 — Key Differences

Property	WPL6	WPL3
Standard	ASTM A420	ASTM A420
Nickel content	None specified	3.18–3.82%
Charpy test temp	−46°C	−101°C
Min YS	240 MPa	275 MPa
EN equivalent	P215NL (1.0473)	P355NL1 (1.0566)
Typical application	LPG, refrigeration	LNG, ethylene, cold gas

Typical Applications

›LNG satellite stations — regasification and send-out piping at −101°C
›Ethylene plants — cold section piping in ethylene cracker fractionation trains
›Propylene refrigeration — cascade refrigeration systems down to −101°C
›Cold box piping — air separation units, nitrogen generation
›Cryogenic storage — transfer lines at LNG terminals and peak-shaving plants

Note: WPL3 is not suitable for liquid nitrogen (−196°C) or LNG boil-off below −101°C. For those services, specify ASTM A403 WP304L or WP316L austenitic stainless steel.

Available Fitting Types — WPL3

Elbows

90° LR · 90° SR · 45° LR · 180° LR/SR · ASME B16.9

Tees

Equal Tee · Reducing Tee · ASME B16.9

Reducers

Concentric · Eccentric · ASME B16.9

Caps

Pipe Cap · ASME B16.9

Stub Ends

Type A · Type B · ASME B16.9

Size Range