Technical Specifications

98
Plastics Technical Manual
A union fitting permits easy disconnection of a piping
system for replacement or repair in the line. Union fittings
consist of three separate parts that when installed properly
join two sections of pipe together.
Installing the union threaded piece and union piece socket
end should be done in accordance with the solvent cementing
instructions provided in this manual. Care should be taken so
that solvent cement does not come into contact with the union
threads or the union face. Note: It is important to remember
Unions
Unions may be damaged by contact with products
containing incompatible chemicals resulting in property
damage or personal injury.
• Do not use lubricants or thread sealants on the union nuts.
• Never use common wrenches or tools designed for metallic
pipe systems. Only use strap wrenches.
• Unions may not be used to draw piping assemblies
together.
• Exceeding recommended pressure rating and/or
temperature rating may result in component damage,
system failure and property damage.
Do not exceed the maximum working pressure of any
system components including pipe, fittings, valves, molded
or cut threads, unions, mechanical coupling or flanges.
• The pressure rating of all components must be reduced at
temperatures above 73 degrees F. Refer to de-rating table
in this manual.
• Exceeding the maximum working temperature or
pressure of the system may result in system failure and
property damage.
INSTALLATION PROCEDURES
to place the union shoulder piece on the pipe prior to solvent
cementing to the pipe. Thread or solvent cement the union
threaded piece to the pipe. The joint should not be disturbed
until it has initially set. Once the joints have properly cured,
ensure that the two mating pieces are flush to one another
prior to tightening the union ring. The ring should not draw
piping systems together or correct improper alignment of the
system. The ring should be hand tightened or tightened with
a strap wrench only.
For information on the pressure ratings of PVC and CPVC schedule 80 unions please refer to the pressure rating of fittings,
flanges, and union sections in the design and engineering section of this manual.