ACT manufactures Hammer Unions from raw materials in the form of forgings or castings in accordance with
service requirements in sizes 1 to 12" with ratings up to 20,000 PSI cold working pressure. Unions for sour gas service
are manufactured in accordance with NACE MR-01-75 & API RP-14E.
ACT's Hammer Unions are interchangeable with WECO or other manufacturers adhering to the industry
Acme thread and line pipe threads are gauged by standard plug & ring gauges.
The conical and spherical surfaces of the female and male subs respectively form an effective metal-to-metal seal in
case of low pressure services.
For medium pressure mostly an '0' ring is provided in the male sub in addition to the metal to metal seal. For high
pressure a lip type seal ring is provided for primary seal in the female sub. The seal protects the secondary metal to
metal seal from corrosion and limits fluid flow turbulence. For sour service applications viton seals are provided.
ACT unions are manufactured using modern manufacturing techniques to attain first class workmanship and
dimensional control. Correctly chosen raw materials for a particular service together with correct heat-treatment
process is used to ensure better service and longer life in extreme conditions.
1. Line pipe threads in Fig-1002, Fig 1502 for Pipe diameters above 4" are not recommended for sour service
2. For Fig-1003, 4" & 5" sizes are rated at 7500 PSI cold working pressure and 12000 PSI test pressure.
3. Sour gas service unions are painted OLIVE GREEN and stamped "NACE".
4. For other types of threading like casing, tubing or NPS thread seal configuration, consult factory.
Quick Reference Table
The following table giving figures of unions, end connections and pressure rating is given for quick reference.
Fig 50. Orange Nut - Orange Subs
These low pressure and suction union of Fig-50 are made from carbon steel. The nut and O-ring are common in both
sizes. Available in 4" or 5" sizes in threaded & socket welded connection. These unions are suitable for 500 PSI wp.
Fig 100. Black nut - Yellow subs
These low pressure unions are ideal for manifold and applications where
CWP does not exceed 1000 PSI.
Fig 200. Blue Nut - Grey subs
These unions are best suited for medium pressure ranges involving air,
water, oil & gas service for cold working pressure upto 2,000 PSI. (For
dimensions see fig. 206). Upto 4" no O-ring is used on the male sub.
Beyond 4" size, an O-Ring is used on the male sub for sealing.
Fig 206. Blue Nut - Grey subs
These unions have an additional 'O' ring on the spherical surface of the
male sub providing a leak proof seal. All dimensions of fig:- 200 & Fig-206
Fig 207. Blue Cap - Grey Subs
These banking unions have a resilient 'O' ring in the blanking cap to
provide an efficient and leak-proof seal suitable for 2000 PSI CWP.
Fig. 211. Blue Subs - Grey Nut
These unions protect against electrolytic action. There is no metal - to -
metal contact between the subs. A resilent seal ring in the female sub
provide additional sealing and protection from corrosion. Suitable for
2000 PSI CWP.
Fig 400. Black Nut - Red Subs
These unions are rigid in design and have all the three parts made of
steel forgings. These unions are best suited for manifold and line
connections. Unions from 3 inch through 8 inch sizes have O- rings for
primary sealing. From 5" to 8" sizes C.W.P. is 2,500 PSI.