Stainless steel adaptor, male/butt weld 316, BSP threaded
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| 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 adaptor, male/butt weld 316, BSP threaded
Stainless steel adaptor, male/butt weld 316, BSP threaded (R taper to ISO 7-1) at one end and plain for butt welding (BW) at the other, from 1/4" to 2" (DN8 to DN50). This short fitting, 22 to 40 mm long depending on size, makes the transition between welded pipework and a screwed fitting. PN 50 up to 40 °C, drinking water compliant, for all fluids compatible with stainless steel.
Description of the stainless steel male/butt weld adaptor
This threaded-to-weld stainless steel fitting is made from welded pipe to ANSI B36.19 SCH.40, in AISI 316 stainless steel, and designed, manufactured and inspected to that standard.
The taper R male end screws into an Rp female tapped thread. The opposite end is plain and chamfered, for butt welding. The body has no flats. The adaptor comes in 8 sizes, from 1/4" (French size 8x13) to 2" (50x60). The 1/2" corresponds to French size 15x21, i.e. DN15.
If the joint must stay removable, choose a stainless steel male/butt weld union instead, PN 20 or PN 40.
Stainless steel adaptor: technical specifications
| Material | AISI 316 stainless steel |
| Manufacture | From welded pipe |
| Standard | Designed, manufactured and inspected to ANSI B36.19 SCH.40 |
| Thread | R taper to ISO 7-1 (BSP, R series), male end. Mates with an Rp female thread (parallel). Not compatible with NPT |
| Weld end | Plain, for butt welding (BW) |
| Connection | Male/butt weld |
| Length | 22 to 40 mm depending on size |
| Nominal pressure | PN 50: 50 bar from −20 to 40 °C, lower above that |
| Temperature | −20/+220 °C, permissible pressure reduced above 40 °C |
| Fluids | All fluids compatible with stainless steel |
| Sizes | 8 sizes, from 1/4" to 2" |
| Compliance | 4MS; drinking water: French order of 25 June 2020 |
Pressure and temperature
PN 50 applies from −20 to 40 °C. Above that, the permissible pressure falls. Values marked ≈ are read from the pressure/temperature curve in the technical data sheet.
| Temperature (°C) | Max. pressure (bar) |
|---|---|
| −20 → 40 | 50 |
| 100 | ≈ 40 |
| 150 | ≈ 35 |
| 220 | ≈ 28 |
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 adaptor is used on drinking water systems and on circuits carrying fluids compatible with 316 stainless steel, where a welded section meets a screwed section. Check fluid compatibility and the permissible pressure at the working temperature.
- Welding: to be carried out by a qualified welder, with the welding process and filler metal defined for the installation. As the thread is close to the weld, apply the thread sealant after welding.
- Thread sealing: an Rp/R joint seals on the threads, using PTFE or jointing compound suited to the fluid and the working temperature.
- Galling: with stainless steel on stainless steel, the thread can gall. Screw in gradually, without forcing.
- Tightening: as it has no flats, hold the adaptor with a strap wrench, not with pipe grips or pliers, which mark stainless steel.
- Dissimilar metals: on a water system, allow for the galvanic couple between stainless steel and galvanized steel or cast iron.
Technical drawing
Dimensions (mm)
L is the overall length. On the drawing, Ø corresponds to the size in inches in the first column. Dimensions in millimetres, PN in bar, weight in kilograms.
| R size | French size | L | PN (bar) | Weight (kg) |
|---|---|---|---|---|
| 1/4" | 8x13 | 22 | 50 | 0.011 |
| 3/8" | 12x17 | 23 | 50 | 0.013 |
| 1/2" | 15x21 | 27 | 50 | 0.027 |
| 3/4" | 20x27 | 32 | 50 | 0.042 |
| 1" | 26x34 | 32 | 50 | 0.064 |
| 1"1/4 | 33x42 | 33 | 50 | 0.079 |
| 1"1/2 | 40x49 | 35 | 50 | 0.108 |
| 2" | 50x60 | 40 | 50 | 0.165 |
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).
| French size | 8x13 | 12x17 | 15x21 | 20x27 | 26x34 | 33x42 | 40x49 | 50x60 |
|---|---|---|---|---|---|---|---|---|
| Inches | 1/4" | 3/8" | 1/2" | 3/4" | 1" | 1"1/4 | 1"1/2 | 2" |
| DN | DN8 | DN10 | DN15 | DN20 | DN25 | DN32 | DN40 | DN50 |
| OD (French size) | 13 mm | 17 mm | 21 mm | 27 mm | 34 mm | 42 mm | 49 mm | 60 mm |
Stainless steel adaptor: frequently asked questions
Adaptor or male/butt weld pipe nipple?
Both connect an R male thread to a weld end. The adaptor is 22 to 40 mm long, from 1/4" to 2". The male/butt weld pipe nipple is 100 or 150 mm long, from 1/4" to 1". Choose according to the space available, the size and the distance you want between the weld and the thread.
What pipe can the plain end be welded to?
The table gives the size in inches and the length, not the outside diameter or the wall thickness in millimetres. Check that it matches your pipe before welding, or contact us.
What is the pressure rating at 100 °C?
≈ 40 bar, against 50 bar from −20 to 40 °C. When fitted with a PN 20 component, the assembly remains limited by that component.
BSP or NPT thread?
BSP to ISO 7-1: R taper thread, sometimes referred to as BSPT, for use with an Rp parallel female thread. This adaptor is not compatible with NPT.
The appearance of the part may vary depending on the batch in stock. Contact us for confirmation.
See also
Full range: all stainless steel BSP fittings
Other stainless steel fittings: stainless steel male/butt weld pipe nipple, stainless steel male/male pipe nipple, stainless steel male/butt weld union PN 20, stainless steel female/female coupling.
Other materials: brass fittings, black malleable iron fittings.
Useful guides:
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