7B BSP Female ISO 1179 Hydraulic Adapter — 7B Adapter

1. What a 7B Adapter Does

The 7B adapter is a straight female-to-female conversion fitting that joins two BSPP male stud ends. Connection 1 and Connection 2 are both female ports machined with ISO 228-1 G parallel pipe thread, and both are produced to ISO 1179 port and stud end practice with a 60 degree cone seat.

Core value: the adapter only works when both female ends match the male stud ends they receive in thread size, thread pitch and cone angle. Matching both ends exactly is the precondition for eliminating leakage at the conversion point, because the 60 degree cone is the surface that carries the seal.

Sealing principle: the joint is sealed by a 60 degree cone seat at each end. The cone on the male stud end seats metal-to-metal against the cone inside the female end, so no bonded seal, O-ring or thread sealant is required for the seal itself. The thread carries the load and centres the joint; it never seals the fluid path.

2. 7B Specifications

The blocks below present the two ends of the 7B adapter symmetrically, so a buyer can read off which port each end receives. Both ends share the same thread family, the same port standard and the same sealing method, which is what makes this a symmetrical female-to-female series.

2.1 Connection 1 — BSP female, 60 degree cone seat (E end)

• Thread standard: ISO 228-1, pipe threads where pressure-tight joints are not made on the threads.
• Thread family: British Standard Pipe Parallel (BSPP / G).
• Gender: female.
• Size range: G1/8″x28 up to G2″x11.
• Sealing method: 60 degree cone seat.
• Mating port standard: ISO 1179 (BSPP port and stud end with 60 degree cone seat).

2.2 Connection 2 — BSP female, 60 degree cone seat (F end)

• Thread standard: ISO 228-1.
• Thread family: British Standard Pipe Parallel (BSPP / G).
• Gender: female.
• Size range: G1/8″x28 up to G2″x11.
• Sealing method: 60 degree cone seat.
• Mating port standard: ISO 1179.
• Note: on this series the F end thread is equal to or larger than the E end thread in every table row.

2.3 Construction and Materials

The body is machined from bar stock on CNC lathes as one piece, so there is no brazed or welded joint in the pressure path. Body material options are carbon steel, 304 stainless steel, 316 stainless steel and brass. Carbon steel bodies are supplied with trivalent chromium zinc plating (Cr3+) or zinc-nickel plating, and stainless steel bodies are supplied bare.

The 7B body carries a single hex across flats, given as S1 in the table, so the whole adapter is tightened from one spanner position. Because the seal is metal-to-metal at the cone, the series contains no elastomer of its own and no seal material has to be chosen for the adapter. Where the mating stud end brings its own bonded seal or O-ring into the joint, select that seal material to suit the fluid and the temperature.

Threads are cut and gauged on the same setup as the hex and the cone, and thread gauges plus dimensional checks are applied batch by batch before packing.

2.4 Pressure and Temperature

Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected. Body size and wall thickness change across the range, so a single catalogue figure cannot be published for every row of the table.

The adapter itself has no elastomer, so its temperature capability follows the fluid, the mating component and the body material: carbon steel with zinc plating for general hydraulic service, and 304 or 316 stainless steel for corrosive and offshore service. Where a bonded seal or O-ring is present elsewhere in the same joint, these material limits apply:

2.5 Part Number and Dimension Table

E and F are the two female thread callouts, E for Connection 1 and F for Connection 2. L is the overall body length and S1 is the hex (spanner flat) size, both in millimetres, and both taken from the drawing above. Thread callouts follow the drawing notation, where G1.1/4″ means G1-1/4″ and G1.1/2″ means G1-1/2″.

3. How to Read a 7B Adapter Part Number

The prefix 7B identifies the series: straight body, female at both ends, ISO 228-1 G parallel thread, 60 degree cone seat to ISO 1179 at each end. One or two size codes follow the prefix and give the BSP size step of each end.

One code means both ends use the same thread size, so 7B-08 is G1/2″x14 at both ends. Two codes mean the ends differ, and the first code is always the E end while the second code is always the F end.

Worked example from the table: 7B-06-08 has E end G3/8″x19 and F end G1/2″x14, with L 33 mm and S1 27 mm. Order that row when a G3/8″ male stud end has to be joined to a G1/2″ male stud end in line. This series carries no dash suffix; the 90 degree version and the bulkhead version of the same family are separate series with their own prefixes, and ordering the wrong prefix is the most common mistake.

4. Installation and Fitment

Inspect both cone seats of a 7B adapter and both thread starts before assembly. Reject any part with a nicked cone, a rolled thread start or a burr inside the port, then wipe the cones clean: a 60 degree cone seat seals only where the two cone surfaces actually touch.

Thread both ends in by hand until the cones contact, then tighten snug and apply the tightening angle specified for the size and material. Never use a long bar on a small hex, and never use thread sealant to compensate for a cone that does not seat, because the sealant will migrate into the fluid path.

Common fitment errors and their symptoms: a BSPT male end fitted into this female end leaks along the thread, because a taper thread defined in ISO 7-1 cannot register on a 60 degree cone; a mis-started thread leaks from the first pressure cycle; over-tightening cracks the hex or flares the female port; and a joint that was run loose shows cone brinelling and will not seal on refitting.

5. Applications and Industries

Application tags for the 7B adapter are hydraulic systems, water jetting, oil and gas equipment, industrial equipment, construction machinery, agriculture, marine and material handling. The pattern behind all of them is the same: two BSPP ports that both use the 60 degree cone seat have to be joined without disturbing either original port.

Concrete scenarios: a maintenance team on a machine that carries two BSPP male test points, where the adapter is the only part needed to join them; a repair bench that keeps the common sizes on the shelf so a damaged port can be re-terminated without re-machining the housing; a component test rig where two male stud ends must be mated in line at full system pressure; and an OEM assembly cell where the adapter is fitted to a manifold before the sub-assembly goes to the test stand.

6. Replacement and Cross-Reference Guide

Identify a replacement by standard and sealing method, never by brand. This is a BSPP female-to-BSPP female part with ISO 228-1 parallel thread and a 60 degree cone seat, so the specification to match is the thread size and pitch of each end plus the cone seat inside each end.

Measure these three things before ordering: first, the outside diameter and threads per inch of the male stud end that must enter each female end, to confirm an ISO 228-1 G thread at 28, 19, 14 or 11 threads per inch; second, the seat inside each female end, confirming a 60 degree cone and not a flat face for a bonded seal; third, the second thread size, taken in the order E then F so the part number is written correctly.

7. Ordering, Packaging and Delivery

To order a 7B adapter, give the series code with the full part number, both thread sizes, the body material, the plating and the quantity. For example: series 7B, part number 7B-06-08, E end G3/8″x19, F end G1/2″x14, carbon steel with zinc-nickel plating, 300 pieces.

Packaging is arranged for distributor shelves and for direct-to-line delivery, with thread protection in transit and labels carrying the part number and both thread sizes. Samples are available for validation, and lead time is confirmed per order once thread sizes, material and quantity are fixed.

8. FAQ

Q1. What is the difference between BSPP and BSPT, and can they be interchanged? BSPP is the parallel pipe thread defined in ISO 228-1 and is the thread used on this series. BSPT is the taper thread defined in ISO 7-1, which seals on the thread flanks and needs a sealant. The two are not interchangeable: a taper male end will not reach a 60 degree cone seat, and forcing it damages both threads and leaks.

Q2. What is the difference between a 60 degree cone seat and a bonded seal, and which should I choose? A 60 degree cone seat seals metal-to-metal between two cones and needs no elastomer, so it suits high temperature work and joints that must not depend on a soft material. A bonded seal is a metal washer with a bonded elastomer ring that seals on a flat face. Choose the cone seat when the mating stud end has a cone, and a bonded seal when the mating port has a flat face.

Q3. How do I identify the correct 7B size? Read the thread callout of both male stud ends. If both are the same size, order the single-code part number, for example 7B-08 for G1/2″x14 at both ends. If they differ, order the double-code part number with the E thread first and the F thread second, for example 7B-06-08 for G3/8″x19 to G1/2″x14.

Q4. What seal material should I select for my fluid and temperature? This series has no elastomer at the seat, so the material decision is the body material: carbon steel with trivalent chromium zinc plating for general hydraulic service, or 304 or 316 stainless steel for corrosive and offshore service. Where a bonded seal or O-ring is used elsewhere in the same joint, NBR covers approximately -30°C to +100°C, FKM approximately -20°C to +200°C, and EPDM approximately -40°C to +120°C.

Q5. How is the working pressure of this adapter determined? Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected. It is governed by the body size and wall thickness and by the pressure class of the mating ports, so no single figure applies to every row. Send the sizes and the expected system pressure with the inquiry and the confirmation is issued with the quotation.

Q6. What is the minimum order quantity and can I get samples? Minimum order quantity depends on the size, the material and the plating selected, and is confirmed with the quotation. Samples are available for validation, and for stainless steel or brass sizes a sample is the normal way to confirm thread fit and cone contact before a production order. Send the part number, the fluid and the annual quantity, and both sample and lead time are confirmed together.

Q7. Can this adapter be re-used after it has been in service? Yes, provided the cone seats are unmarked and the threads are undamaged. Inspect both cones for brinelling or a bright contact ring after removal, and replace the part if a cone has been deformed by over-tightening. Re-using a part that has been run loose usually produces a joint that weeps at the first pressure cycle.

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