Black Sockets
A black socket is a malleable cast iron fitting with two female-threaded ends that joins two threaded black steel pipes of the same size end to end in a straight line. It is the simplest connection when the pipe length is not enough or an intermediate joint is needed.
Sockets have the widest size range in the black fittings family: 12 sizes from small 1/8″ appliance connections up to 4″ main risers. They are used as straight joints in heating, gas, steam and compressed air lines.
Main Applications
- Joining pipes on long routes
- Straight connections in heating and boiler lines
- Extending pipes in indoor gas lines (in projects compliant with regulations)
- Compressed air and pneumatic lines
- Small-bore measuring and control lines (1/8″ – 3/8″)
- Creating a female-threaded port at a pipe end
Technical Data
| Fitting type | Straight socket, two female-threaded ends of the same size |
|---|---|
| Product standard | TS EN 10242, design symbol A (manufacturer information) |
| Material | Blackheart malleable cast iron B 350-10 (sales sheet information) |
| Surface | Black, without galvanized coating |
| Thread | ISO 7-1 Rp parallel female thread |
| Sizes | 1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1 1/4″, 1 1/2″, 2″, 2 1/2″, 3″, 4″ (product range) |
| Other type | Test socket (product range) |
| Permissible pressure | 25 bar, −20 … +120 °C (EN 10242, design A) |
| Pressure at high temperature | 20 bar, up to +300 °C (EN 10242, design A) |
| Leak test | At least 5 bar air or 20 bar water (sales sheet information) |
| Joint between different sizes | With a black reducing socket |
| Detachable joint | With a black taper seat union or swivel union |
Material Options
| Part | Black malleable iron | Galvanized malleable iron | Stainless steel casting |
|---|---|---|---|
| Body | Blackheart malleable cast iron B 350-10 | Malleable iron EN-GJMB-350-10, hot-dip galvanized | Investment casting 1.4408 (AISI 316 equivalent) or 1.4308 (AISI 304 equivalent) |
| Surface | Black, uncoated | Zinc coated | Stainless, uncoated |
| Thread | ISO 7-1 Rp female thread | ISO 7-1 Rp female thread | Depending on model |
| Pressure rating | 25 bar −20…120 °C, 20 bar 300 °C (EN 10242) | 25 bar −20…120 °C (EN 10242) | Depending on model |
| Suitable media | Closed heating water, gas, compressed air | Drinking and domestic water, fire water | Corrosive media and media requiring hygiene |
Which material? Using a black socket on a black pipeline keeps surface and corrosion behaviour the same; use galvanized sockets on galvanized pipe and stainless sockets on stainless pipe.
Advantages
Simplest Joint
- Two pipe ends join with a single piece
- No special tools needed
Widest Size Range
- 12 sizes from 1/8″ to 4″
Compact Length
- Takes up roughly the pipe diameter in the line
Heat and Pressure Rating
- 25 bar to EN 10242, 20 bar at +300 °C
Construction and Design Features
- Symmetrical body, both ends the same size with the same Rp thread
- Smooth outer surface with casting flash removed
- Test socket with an additional port for measuring (depending on model)
- Design A wall thickness, EN 10242 pressure table
Just send the socket size and quantity; we will confirm stock for all sizes from 1/8″ to 4″ right away.
How to Choose?
- Measure the pipe sizeBoth pipes to be joined must be the same size; if not, choose a reducing socket.
- Consider dismantlingIf the joint will be opened later, use a taper seat union or swivel union instead of a socket.
- Check operating valuesCompare pressure and temperature with the EN 10242 limits.
- Match the surface to the pipePrefer black sockets on black pipe and galvanized sockets on galvanized pipe.
Complementary Products
Why ORFA?
Other Threaded Black Fittings
Threaded Black Tees
Threaded black tees are equal-size fittings used to split flow in three directions on threaded black steel pipelines.
Details →
Black 45° Elbows
Black 45° elbows are fittings used to change direction by 45 degrees on threaded black steel pipelines.
Details →
Black Pipe Crossover Bends
Black pipe crossover bends are curved fittings used to pass over another pipe on threaded black steel lines.
Details →
Black Unions
Black unions are fittings that join two threaded black steel pipes in a way that can be taken apart again.
Details →
Black Elbows
Black elbows are fittings used to change direction by 90 degrees on threaded black steel pipelines.
Details →
Black Reducing Tees
Black reducing tees are fittings used to take a smaller branch off the main run on threaded black steel lines.
Details →
Black Conical Unions
Black conical unions provide a tight, removable connection on threaded black steel pipes through a conical seat.
Details →
Black Plugs and Caps
Black plugs and caps are used to close the ends of threaded black steel pipes and fittings.
Details →
Black Crosses
Black crosses are fittings that split flow in four directions on threaded black steel pipelines.
Details →
Black Street Elbows
Black street elbows have one female and one male threaded end and change direction on black steel lines without an extra nipple.
Details →
Black Reducing Sockets
Black reducing sockets are female threaded fittings that join two black steel pipes of different sizes.
Details →
Black Nipples
Black nipples are short black steel pieces with male threads on both ends, used to connect two female threaded fittings.
Details →
Black Reducing Bushes
Black reducing bushes are fittings with male and female threads used to change pipe size on threaded black steel lines.
Details →Get a quote for your project
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