BS3799 Forged Fittings

BS 3799: 1974 Specification for steel pipe fittings, screwed and socket-welding for the petroleum industry.This standard covers ratings, dimensions, tolerances, marking, and material requirements for both Socket Weld Fittings  and Threaded Fittings. And today, we focus on the BS3799 Forged Threaded Fittings,

Forged Threaded Fittings are mainly including Threaded Elbow, Threaded Tee, Threaded Cross, Threaded Couplings, Threaded Cap, Threaded Plug, Threaded Bushing, Threadolet, Threaded Union and Threaded Nipple.

They are mainly used in small diameter pipes with low pressure. The oldest pipe system connecting method may be thread.

Threaded Fittings often found in low-cost, noncritical applications such as domestic water system. And available in stainless steel, carbon steel and alloy steel.

BS3799 Forged Threaded Fittings Classification

Degree for Threaded Elbow.

It is usually 45 degree threaded elbow and 90 degree elbow and wildly used in changing the direction of flow.

Threaded Tee and Cross

They are used to provide branches for the run pipe. There are equal tee, equal cross and reducing tee, reducing cross.

Thredolet

Threadolet usually as reinforced branch connection, it replaces threaded reducing tee which is one type of BS3799 forged threaded fittings.

Threaded Full and Half Coupling

Full Coupling and Half couplings are all belong to threaded couplings. The differences is full coupling has threads at both ends, and half coupling has one end only. That means full coupling can connect pipes or fittings at both ends and half coupling only one end can.

Threaded Cap

It has the same function with threaded plug. They are all used to seal pipeline.

Threaded Bushing

It can be hex head bushing and flash bushing. Hex reducing bushing plays an irreplaceable role in pipe connection.

Concentric and Eccentric Swage Nipple

Concentric Swage and Eccentric Swage have thread type and they are a very practical. They can avoid deposition of flows.

Threaded Union

It is a common connection fitting. A complete union shall consist of three parts: male end, female end, and nut. The two ends connect two pipes, and the nut connects the two ends like a coupling.

Threaded Fittings Dimensions

1. The diameter is usually between DN6 to DN100 (NPS 1/8-4), threaded swage nipple and unions have larger range up to DN80 (3 inch).
2. The pressure rating is 2000LB, 3000LB, 6000LB. Pipe coupling and cap have 3000# and 6000# only. Plug has no pressure rating.
3. Materials shall conform to the requirements for the WP seamless construction materials. It is including ASTM Fitting Specifications A234, A403, A420, A815, or B366 or ASTM forging fittings specifications A105, A182, A350, B462, or B564.

4. Thread Type

• NPT is American thread seal pipe thread, thread angle is 60 deg. Conicity is 1:16. Both internal and external thread are RC. AMSE B16.11 fittings use NPT more often.
• BSP is the international common thread seal pipe thread. Thread angle is 55 degree, conicity is 1:16. BS3799 fittings use BSP more.

Advantages for Threaded Fittings

1. Low production cost.
2. Convenient assembly and disassembly, high installation efficiency.
3. The connection doesn’t need professional personnel. It does no damage to galvanized coating of pipes or fittings. Safe to installation.
4. Has good leakage proof in low pressure, low temperature vibration less piping.

Disadvantage for Threaded Fittings

1. Rapid temperature changes may lead to leaks.
2. Vibration can result in fatigue failures.
3. In hazardous pipe systems threaded fittings should be avoided.

Forged Threaded Fittings Stockholders

Zizi engineering is BS3799 Forged Threaded Fittings Stockholders in China and export to Asia, Africa, Middle East, Latin America and Oceania. Forged fittings of regular size and normal material are always in stock.

You are always to get best service whatever big or small order.