NPT Thread Options

npt threads

National Pipe Thread (NPT) Part Number Conversion

Many of the more popular ILME hoods and surface mount bases are available with NPT threads from the factory. For those that are not available from the factory with NPT threads, adapters are used to convert them to NPT.

Whether tapped NPT or converted to NPT, the part numbers change slightly to reflect the thread size. Below is an example of how you would change a CHO-10L hood from a PG16 threaded opening to a ½” NPT opening, resulting in the part number CHOT-10.4L.

To change the part number, add the letter “T” to the end of the part number prefix (e.g. CHO becomes CHOT.) The thread size (ILME Suffix) is then inserted in the part number immediately after the pole count (e.g. -10L becomes -10.4L). These steps change the CHO-10L with a PG16 opening to a CHOT-10.4L with a ½” NPT opening. Likewise, a CHO-10 would become CHOT-10.4. However, if the ILME part number has a thread size referenced in it, that thread size reference is dropped before converting. For example, a CAO-24.29 becomes CAOT-24.6 or CAO-24L29 becomes CAOT-24.6L.

If you have a double opening, add “/2” after the suffix (e.g. CHP-10LS2 becomes CHPT-10.4/2LS).

We are also able to provide enlargers and reducers should your application require a step down or up of multiple levels.

Please contact the factory for assistance.

PG SizeNPT ConversionILME Suffix
PG11 3/8" .3
PG11 1/2" .4
PG13.5 1/2" .4
PG16 1/2" .4
PG21 3/4" .5
PG29 1" .6
PG36 1.25" .7
PG42 1.5" .8
Metric SizeNPT ConversionILME Suffix
M16 1/2" .4
M20 1/2" .4
M25 3/4" .5
M32 3/4" .5
M32 1" .6
M40 1.25" .7
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