Threaded Pipe Nipples

Male x male NPT threaded pipe nipples: connecting two female threaded fittings

A male x male NPT threaded pipe nipple connects two components that each have a female NPT connection. It can be used between a tank, valve, bulkhead fitting or another threaded fitting when both connections are female.

Agrico Plastics offers male x male NPT threaded pipe nipples in Schedule 80 glass-reinforced polypropylene and Schedule 80 PVC. This category also includes a 3/4" brass fitting designed to transition between a male garden hose thread and a male NPT thread.

Standard NPT pipe nipples have a male NPT thread at each end, with both connections being the same size. If the two NPT connections are different sizes, a male x male reducing fitting should be considered instead. The brass garden hose fitting is different because its two ends use different thread types.

What is a male x male pipe nipple used for?

A pipe nipple is used when two components that need to be connected both have female NPT threaded connections.

For example, a valve with a female NPT connection cannot be threaded directly onto another female NPT fitting. A male connection must be added between them. This is exactly what the pipe nipple provides.

This small fitting makes it possible to build or modify an assembly without replacing components simply because both have female connections.

Check both connections before selecting a fitting

Diameter is not the only information that needs to be checked.

• Check whether each connection is male or female;
• Identify the thread type on each side;
• Check the size of both connections;
• Select a material suitable for the liquid and installation;
• Check the available space between components.

The last point is easy to overlook. Two fittings may be compatible on paper, but the assembly must also provide enough space to properly thread the different components together.

Straight pipe nipple, reducer or garden hose fitting?

The correct fitting depends on the two connections that actually need to be joined.

This check helps prevent selecting a fitting that has the correct nominal diameter but the wrong connection or thread type.

Reinforced polypropylene, PVC or brass?

The standard NPT pipe nipples in this category are available in Schedule 80 glass-reinforced polypropylene and Schedule 80 PVC. The 3/4" garden hose fitting is made of brass.

Material should not be selected solely according to appearance or price. When the fitting is used with a chemical product, compatibility between the liquid and the fitting material, as well as all other wetted components, should be checked.

Operating temperature must also be considered. The characteristics of a reinforced polypropylene fitting are not automatically the same as those of a PVC or brass fitting.

If your installation already includes valves, bulkhead fittings or other fittings, consider the complete assembly rather than evaluating only one component.

The same diameter does not always mean the same connection

Seeing “3/4"” or “2"” on two components is not enough to conclude that they can be connected directly.

You also need to determine whether each connection is male or female and which thread type is used. The standard pipe nipples in this category have male NPT threads.

This is particularly important when adding a fitting to existing equipment. Before ordering a component based only on the stated diameter, identify both connections that need to be joined.

The 3/4" brass garden hose fitting is different

This category also includes a 3/4" brass garden hose fitting that does not perform exactly the same function as the polypropylene or PVC male x male NPT pipe nipples.

It has a male garden hose thread on one side and a male NPT thread on the other. It therefore provides a transition between these two connection types.

This distinction is important: two fittings may both be identified as 3/4" without having the same thread. A garden hose thread and an NPT thread should not be considered interchangeable simply because they have the same nominal size.

This fitting is useful when a female NPT connection on a tank or other equipment needs to be adapted for connection to a garden hose.

Pipe nipple length can also matter

Most installations simply require a pipe nipple long enough to connect the two components.

In some configurations, however, additional space may be required between the fittings. Agrico offers a 2" x 6" long reinforced polypropylene pipe nipple for this type of situation.

Diameter should therefore not be the only consideration. If the components need to be spaced apart or their shape prevents them from being positioned close enough together, also check the required length.

When is another type of fitting more appropriate?

A male x male pipe nipple is particularly simple when creating a threaded connection that will remain assembled.

If the installation needs to be disconnected frequently, another type of fitting may be more practical. A Camlock fitting, for example, can allow parts of an installation to be connected and disconnected without repeatedly unthreading a connection.

Likewise, if the two NPT connections are different sizes, consider a male x male reducing fitting instead.

The correct fitting therefore depends less on the name of the part than on the two connections that actually need to be joined.

Frequently asked questions

What is a male x male threaded pipe nipple used for?

It is primarily used to connect two components that each have a female NPT threaded connection.

Can I use a 2" pipe nipple between any two 2" connections?

No. Size alone is not enough. The connections must also have the correct thread type and be compatible with a male NPT connection.

Is a 3/4" garden hose thread the same as a 3/4" NPT thread?

No. Although both are identified as 3/4", they are different thread types. The brass fitting offered in this category has a male garden hose thread on one side and a male NPT thread on the other to provide the transition between them.

What is the difference between a pipe nipple and a male x male reducer?

A straight pipe nipple connects two NPT connections of the same size. A male x male reducer changes from one size to another while maintaining a male threaded connection at each end.

Should I choose reinforced polypropylene, PVC or brass?

It depends on the connection type, liquid, operating temperature and other components in the installation. The brass fitting in this category serves the specific purpose of transitioning between a garden hose thread and an NPT thread. For chemical applications, material compatibility with the product should be checked before selecting a fitting.