Plumbing – the proper method to install a “close” metal pipe nipple


A close pipe nipple is designed so that when it is installed there is very little or no gap between the two fittings which attach to either end.

What is the proper method to install one of these? Could be black iron, brass, etc.

Here are the issues I wonder about:

  • When attaching the nipple to the first fitting, it seems you would have to grip the nipple by the threads with a pipe wrench. This may cause damage. Perhaps a protective padding is used?

  • When attaching the second fitting, how to ensure the nipple is inserted more or less evenly? The insertion torque may continue to tighten it into the first fitting which would be hard to prevent or even observe.

  • Should you just tighten both fittings simultaneously?

Example of a close nipple:

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Best Answer

Installing the close nipple is done by starting the nipple into the first fitting by hand. Then start the second fitting. Make sure that the suitable teflon pipe thread tape is installed on both ends of the close nipple. Then use an appropriate wrench on the second fitting to tighten the joints.

Note that the threads on a nipple like this should have a diameter taper on each end. This causes the fitting to get progressively tighter as each end is screwed into its mating part. When tightening the two joints simultaneously the two tapered joints will turn till one gets tighter than the other. At that point the looser one will then tighten up till it catches up and becomes similar tight to the other joint. Eventually you will achieve the necessary thread engagement with each end of the nipple.