Hammer Union Seals
A hammer union comprises of a thread end, a nut end and a hammer nut which, when cinched up, compresses a composite seal assembly thereby preventing leakage. The seal assembly comprises a metal insert of a size to pass into the seal groove of conventional hammer unions and a small seal acting between the insert, the thread end and the nut end. The small seal is conveniently an O-ring or a Hammer Union Seal (Lip Seal) and is of a size that is compressed when the seal assembly is inserted into the thread end of the hammer union.
Proven Seal Designs
High-Pressure Services (6,000 to 20,000 psi)
Hammer Unions for high-pressure services feature a replaceable, lip-type seal ring in the female sub. This primary seal protects the secondary metal-to-metal seal from abrasion and corrosion while minimizing flow turbulence.
Non-Pressure Seal Thread Hammer Union
This type is especially designed for abrasive, high-pressure (15,000 psi) Hammer Union services where welded connections are undesirable. This design provides strong, permanent end connections without butt welding. The union ends are shop assembled to pipe or tubing. An epoxy thread compound is used to secure the connection. Since all threads are isolated from the fluid line, the resulting smooth bore assures minimum turbulence, decreased washout and reduced buildup around pipe ends of acid, sand, cement or chemicals. Connecting threads are API 10 round.
NBR Brass Ring
HNBR Stainless Ring
VITON Stainless Ring
Recommended service: Cementing, fracturing, acidizing, testing, and choke-and-kill lines
Positive sealing: Primary elastomer seal and metal-to-metal seal combine to deliver positive sealing throughout the stated pressure range.
Hammer unions use a special rubber seal ring for positive sealing with minimum torque. This ring snap-fits into a detent within the hub to prevent its loss. Hammer unions are available in 1 in. to 4 in. line pipe sizes.
Seal Size: 1”, 1-1/4”, 1-1/2”, 2”, 2-1/2”, 3”, 4”
Seal Material: NBR, HSN, Viton and PTFE