A pipe clamp is used to connect and seal two pieces of round pipe. There are two pipe clamp styles used worldwide. The first is a traditional pipe clamp, which consists of a horseshoe-shaped piece of round stock with threads on each end and a half-round piece of flat stock with holes in each end; the threaded ends of the first piece can pass through and be tightened by a pair of lock nuts. The second type of pipe clamp is a flat band clamp. This type of clamp is used primarily on stainless steel exhaust pipe and is intended to seal the joint without distorting the shape of the pipe. The flat piece of soft stainless steel is wrapped around the connecting pipes at the joint, and a bolt is tightened, fastening the two ends of the pipe clamp together and sealing the connection.
When applying a pipe clamp to an exhaust pipe on a vehicle or in a plumbing application, it is best to never over-tighten the clamp. Doing so can distort the pipe, often resulting in a leak that cannot be sealed. The over-tightened clamp can also create a crushed pipe that will not be able to be separated in the future. The key to a properly sealed clamp is to apply equal pressure to both sides of the clamp and turn the nuts one full turn with a wrench after they become finger tight.
The use of plastic plumbing pipe creates another issue when choosing a pipe clamp. The band-type clamp is the clamp of choice in this application as it will not as easily crush or crack the plastic pipe. If simply using a clamp to hang or support a plastic pipe, a flat cradle clamp is usually the proper choice. It does not surround the pipe, but instead forms a cradle-type support which is suspended from a long, threaded rod attached to a floor or ceiling joist.
Pipe clamps that are subjected to high heat, such as a vehicle's exhaust pipe clamp, should be installed with anti-seize compound applied to the threads of the clamp. This can help ensure that the clamp can be easily removed in the future should the need arise. This is especially helpful on a show-type vehicle's chrome exhaust pipe. The application of anti-seize under the clamp as well as inside of the mating surfaces of the exhaust pipes themselves can also aid in the removal of the system when necessary.