Black Reducing Sockets
A black reducing socket is a malleable cast iron fitting with two female-threaded ends that joins two threaded black steel pipes of different sizes in a straight line. The size transition and the pipe joint are made in one piece.
It is used when moving from the main line to a smaller line and where pump and valve ports differ from the pipe size. 21 size combinations from 1/2″ × 3/8″ to 4″ × 3″ are available.
Main Applications
- Straight transition from the main line to a smaller line
- Matching pump suction and discharge port sizes
- Size reduction at manifold outlets
- Transition to machine connections in compressed air lines
- Riser size changes in gas lines (in projects compliant with regulations)
- Stepwise size reduction in heating circuits
Technical Data
| Fitting type | Reducing socket, two female-threaded ends |
|---|---|
| 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, different size on each end |
| Size range | 1/2″ × 3/8″ – 4″ × 3″ (product range) |
| Example sizes | 3/4″ × 1/2″, 1″ × 3/4″, 1 1/2″ × 1″, 2″ × 1 1/2″, 3″ × 2″ (product range) |
| Number of sizes | 21 combinations (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) |
| Male-female transition | With a black reducing bush |
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), depending on model |
| Surface | Black, uncoated | Zinc coated | Stainless, uncoated |
| Thread | ISO 7-1 Rp female thread (two sizes) | ISO 7-1 Rp female thread (two sizes) | 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? If both pipes at the transition are black, use a black reducing socket; choose galvanized for drinking water lines and stainless for chemical lines.
Advantages
Joint and Transition in One
- One body instead of a socket plus reducer
- One less threaded joint
Wide Size Choice
- 21 combinations, up to 4″ × 3″
Straight Line
- The transition is made on the pipe axis without an extra turn
Heat Resistance
- Rated 20 bar at +300 °C
Construction and Design Features
- Both ends on the same axis with Rp female threads of different sizes
- Stepped internal transition from the large to the small end
- One-piece cast body
- TS EN 10242 design A
Send the large and small size (e.g. 2″ × 1 1/2″) and the quantity; we will confirm the suitable reducing socket from stock right away.
How to Choose?
- Measure both pipe sizesDetermine the large and small pipe sizes in inches.
- Choose the connection typeIf both sides are pipe, use a reducing socket; if one side is a female-threaded fitting, use a reducing bush.
- State the size correctlyGive the size in the order large × small when ordering.
- Check pressure and temperatureMake sure pressure and temperature at the transition stay within 25 bar/120 °C or 20 bar/300 °C.
Complementary Products
Why ORFA?
Other Threaded Black Fittings
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Black Conical Unions
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Black Plugs and Caps
Black plugs and caps are used to close the ends of threaded black steel pipes and fittings.
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Black Crosses
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Black Street Elbows
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Black Sockets
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Black Nipples
Black nipples are short black steel pieces with male threads on both ends, used to connect two female threaded fittings.
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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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