Glossary

Toilet Threads

Unlike tapered threads, thread sealants should not be used with straight threads, and may actually interfere with proper installation, causing them to leak - or the sealant can act as a lubricant and make it hard to tell if the connection is overtightened. Connections should be firmly and securely tightened against the seal, but care should be taken to avoid over-tightening the joint. For metal fittings, hand tight plus 1/4 to 1/2 turn is usually sufficient. Plastic WingNut Fittings are designed to be hand tightened only, without the use of tools.

For example: A 7/8" IPS straight thread fits Toilet connections. Same as 15/16" NPS and 7/8" Slip Joint or 7/8" Ballcock.

See: Straight Pipe Threads

Compression

Make sure that you have a good fit and length, and that the tube or pipe is inserted fully into the fitting before you tighten the nut, because once the sleeve is formed, it cannot be removed from the tube. To replace a stop valve of this type, you usually will have to use the existing nut and sleeve unless the pipe extends far enough from the wall to cut it off and install new. It's best to wait until you have to cut the copper pipe, because if it gets too short, you will have to go into the wall to replace it. Thread sealants should not be used on compression joints, and may actually interfere with proper installation, causing them to leak - or the sealant can act as a lubricant and make it hard to tell if the connection is overtightened.

Also applies to flexible connectors that have a nut and gasket designed to attach directly to an SAE standard compression thread, without the use of a sleeve or ferrule.

See: NOM Comp, Nominal Compression

Like PVC, but withstands higher temperatures.

Escutcheon

Faucet Threads

Unlike tapered threads, thread sealants should not be used with straight threads, and may actually interfere with proper installation, causing them to leak - or the sealant can act as a lubricant and make it hard to tell if the connection is overtightened. Connections should be firmly and securely tightened against the seal, but care should be taken to avoid over-tightening the joint. For metal fittings, hand tight plus 1/4 to 1/2 turn is usually sufficient. Plastic WingNut Fittings are designed to be hand tightened only, without the use of tools.

For example: A 1/2" FIP straight thread fits standard 1/2" trade size Faucet Connections (1/2" ID-7/8" OD). Same as 7/8"-14 NPS and 1/2" IPS or 1/2" Slip Joint.

See: Straight Pipe Threads

Water Connector

Select a connector of adequate length to avoid sharp bends. Connections should be firmly and securely tightened against the seal, but care should be taken to avoid over-tightening the joint. For metal fittings, hand tight plus 1/4 to 1/2 turn is usually sufficient. Plastic WingNut Fittings are designed to be hand tightened only, without the use of tools.

Also Plain and Corrugated Metal types.

See: Riser

Slip Joint

See: Straight Pipe Threads

Nominal Compression

For example: 1/2" NOM Comp. fittings are actually standard 5/8" SAE compression fittings, because the 1/2" I.D. trade size copper pipe is 5/8" O.D.  A 1/2" NOM Comp stop valve would attach directly to a 5/8" OD (1/2" trade size) copper pipe where it comes out of the wall.

See: Compression

Flex Riser

Use care when installing all metal types, as they will work harden and crack or break if they are bent repeatedly in the same place. Select a connector of adequate length to avoid sharp bends, and bend gradually. A sharp bend or too short in length may put a kink in the tube, causing it to fail prematurely.

See: Flexible Water Connector

Threads

UNC, UNF

Not for Pipe Connections.

For example: A 1/2"-13 SAE thread is 1/2" OD - 13 Threads Per Inch.

A 1/2"-20 SAE thread is 1/2" OD - 20 Threads Per Inch.

Same as 1/2-13 UNC and 1/2-20 UNF

IPS

See: Straight Pipe Threads

A 3/8"-16 Stem is a 3/8" diameter solid rod with UNC threads.

A 3/8" NPT Stem is a 3/8" trade size pipe, with tapered pipe threads.

Also the part that turns on a stop valve or faucet.

Supply Stops,

Straight Stops,

Angle Stops.

FIP Straight,

MIP Straight,

NPS, IPS, Slip Joint,

Faucet Threads,

Toilet Threads.

Unlike tapered threads, thread sealants should not be used with straight threads, and may actually interfere with proper installation, causing them to leak - or the sealant can act as a lubricant and make it hard to tell if the connection is overtightened. Connections should be firmly and securely tightened against the seal, but care should be taken to avoid over-tightening the joint. For metal fittings, hand tight plus 1/4 to 1/2 turn is usually sufficient. Plastic WingNut Fittings are designed to be hand tightened only, without the use of tools.

For example: A 1/2" FIP straight thread fits standard 1/2" trade size Iron pipe or Faucet Connections (1/2" ID-7/8" OD). Same as 7/8"-14 NPS and 1/2" IPS or Slip Joint.

For example: A 7/8" IPS straight thread fits Toilet connections. Same as 15/16" NPS and 7/8" Slip Joint or Ballcock.

Straight pipe threads do not form a tight seal, but are often used with a flange, gasket and locknut where a pipe or valve goes through a tank wall.

Also used with a gasket or nosecone seal for 1/2" IPS Faucet and angle stop connections, 1/2" Iron Pipe Connections, 7/8" IPS Toilet connections, etc. Same as Slip Joint.

See: Tapered Pipe Threads

NOM Sweat,

Nominal Sweat,

Solder Connection

For example: 1/2" NOM Sweat fittings are actually 5/8" ID, because the 1/2" I.D. trade size copper pipe is 5/8" O.D.  A 1/2" NOM Sweat stop valve would be soldered directly to a 5/8" OD (1/2" trade size) copper pipe where it comes out of the wall.

Be sure that the pipe is cut squarely, and that all parts are clean metal before soldering. Use care to avoid getting the stop valve too hot when soldering. A wet rag may help. Be very careful not to let solder and/or acid fluxes drip on other nearby connectors and fittings, especially any kind of flexible gas connectors.

Threads

FIP, MIP, NPT

For example: A 1/2" FIP thread fits standard 1/2" trade size Iron pipe (1/2" ID-7/8" OD). Same as 7/8"-14 NPT.

Tapered pipe threads do not need a gasket or cone seal, but a thread sealant must be applied to the male threads only, before the joint is assembled. Use care to avoid getting sealant inside the pipe. Unlike straight threads, tapered thread joints seal better the more they are tightened, making them essential for leak free Iron Pipe joints.

A female straight thread fitting or slip joint connection may be attached to a tapered male thread, as long as a gasket or seal is incorporated into the female fitting design. A thread sealant alone would not seal.  In this case, a thread sealant may actually interfere with proper installation, causing the joint to to leak.

Female tapered threads are not suitable for Faucet or Toilet Connections. Even if you use a thread sealant, a female tapered thread fitting may not seal if it is attached to a male straight thread like a faucet or toilet connection.

Generally, do not mix Tapered with Straight Thread pipes and fittings unless special seals are provided.

See: Straight Pipe Threads

A standard kind of Coarse straight thread used on fittings, nuts, and bolts.

Not for Pipe Connections.

A standard kind of Fine straight thread used on fittings, nuts, and bolts.

Not for Pipe Connections.