Stainless steel butt weld union 316L, PN 40, weld ends both sides

$34.00

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Size

Ø 21.3 mm (1/2") Ø 26.9 mm (3/4") Ø 33.7 mm (1") Ø 42.4 mm (1"1/4) Ø 48.3 mm (1"1/2) Ø 60.3 mm (2")

Product variants

Shipping and Delivery

Product Type	Delivery Method	Preparation Time	Transport Time	Delivery Time
All Parts	Pickup Point	0 to 3 days	3 to 6 days	3 to 9 days
All Parts	Home Delivery	0 to 3 days	3 to 5 days	3 to 8 days
Tubes > 90cm	Home Delivery	0 to 3 days	3 to 5 days	3 to 8 days
Tubes < 200cm	Home Delivery	0 to 3 days	3 to 5 days	3 to 8 days
Tubes > 200cm	Home Delivery	0 to 6 days	6 to 10 days	6 to 16 days
Assembled Products	Home Delivery & Pickup Point	0 to 5 days	(see methods)	3 to 11 days

* Tubes longer than 90cm cannot be delivered to a pickup point

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Stainless steel butt weld union 316L, PN 40, machined, for welded pipework from Ø 21.3 to Ø 60.3 mm (sizes 1/2" to 2", DN15 to DN50). Its two plain ends are butt welded (BW) and its nut provides a point of disconnection on the line. PN 40, drinking water compliant, for all fluids compatible with stainless steel.

Description of the machined stainless steel butt weld union 316L PN 40

Two 316L stainless steel ends and a CF8M stainless steel nut make up this 3-piece stainless steel union. 316L is the low-carbon version of 316. The nominal pressure is 40 bar (PN 40). The seal is metal to metal at the conical seat, and the nut undoes to separate the two sections of pipework.

One end is 6-sided (dimension M2 on the drawing), the other has no flats. Does one side need to screw on? Choose the stainless steel female/butt weld union 316L PN 40 or the stainless steel male/butt weld union 316L PN 40.

Stainless steel butt weld union 316L: technical specifications

Material	316L stainless steel ends, CF8M stainless steel nut
Manufacture	Machined conical (taper) seat union
Standard	ISO 4144
Type	3-piece: two weld ends and a nut
Seal at the seat	Metal to metal
Shape	One end 6-sided, the other without flats, nut with flats
Connection	Butt weld (BW) at both ends; Ø = outside diameter of the end
Ends	2 weld ends
Nominal pressure	PN 40. Permissible pressure falls as temperature rises
Temperature	Stated range −20/+220 °C, with no high-temperature pressure values: consult us for hot applications
Fluids	All fluids compatible with stainless steel
Sizes	6 sizes, from Ø 21.3 to Ø 60.3 mm (1/2" to 2")
Compliance	4MS; drinking water: French order of 25 June 2020

Pressure and temperature

This union is rated PN 40. The permissible pressure falls as temperature rises, and we have no high-temperature pressure curve for this part. The stated range of −20 to +220 °C therefore does not mean PN 40 across the whole range. For hot applications, contact us before choosing.

Certification and compliance

According to the technical data sheet for the series:

4MS: compliant with the 4MS requirements, the harmonized European rules for materials and products in contact with drinking water.
Drinking water: compliant with the French order (arrêté) of 25 June 2020 on metallic materials and products in contact with water intended for human consumption.

Uses and installation advice

This union is used on welded pipework in drinking water systems and in circuits carrying fluids compatible with stainless steel, where a point on the line must stay removable. Check the fluid’s compatibility with 316L and CF8M.

Welding: to be carried out by a qualified welder. The welding process and filler metal depend on the installation.
Before welding: dismantle the union and separate the ends to protect the conical seat. Keep the seat clean at every reassembly.
Galling: with stainless steel on stainless steel, the nut can gall. Screw it on gradually, without forcing.
Tightening: use an open-ended or adjustable spanner to hold the end with flats and tighten the nut the same way, not with pipe grips or pliers, which mark stainless steel. Hold the end without flats with a strap wrench.

Technical drawing

Dimensions (mm)

L: overall length. Ø: outside diameter of the weld ends. M1: length of the nut. M2: length of the flats on the end. Dimensions in millimetres, PN in bar, weight in kilograms.

Size	French size	Ø	M1	M2	L	PN (bar)	Weight (kg)
1/2"	15x21	21.3	16	9	48	40	0.133
3/4"	20x27	26.9	17	9	52	40	0.189
1"	26x34	33.7	18	9	54.5	40	0.271
1"1/4	33x42	42.4	18	10	56	40	0.351
1"1/2	40x49	48.3	18	10	58	40	0.454
2"	50x60	60.3	20	12	63	40	0.606

Size conversion

Conversion between the French size designation, inches, DN and the outside diameter stated in the designation (a rounded value, not a pipe dimension). The actual diameter of the end is dimension Ø.

French size	15x21	20x27	26x34	33x42	40x49	50x60
Inches	1/2"	3/4"	1"	1"1/4	1"1/2	2"
DN	DN15	DN20	DN25	DN32	DN40	DN50
OD (French size)	21 mm	27 mm	34 mm	42 mm	49 mm	60 mm

Stainless steel butt weld union 316L: frequently asked questions

PN 40 or PN 20?

The choice depends on the working pressure at the working temperature. A PN 20 union is not suitable if your installation requires PN 40. The PN 20 model starts at the 1/4" size and publishes its high-temperature values. This one starts at 1/2".

What is the pressure rating at high temperature?

We have no figure for this part. Contact us with the diameter, fluid, temperature and working pressure.

Which parts are welded?

The two 316L ends. The CF8M nut is not welded.

The appearance of the part may vary depending on the batch in stock. Contact us for confirmation.

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