How to determine the threads of the diaphragm accumulator?

Milehertz diaphragm accumulator needs to be connected to the pipeline through threads, so it is particularly important to determine the size and type of the threads. The following are several methods for determining the type of threads:

一．Use a plug gauge (to detect internal threads) or a ring gauge (to detect external threads) to determine the thread type

The simplest and most accurate method is to use a plug gauge or a ring gauge to make the judgment. Screw the plug gauge or ring gauge into the thread to be tested. The through gauge can be easily screwed in to the bottom, and the NO-go Gauge can only be screwed in 2 threads at most. In this case, the accumulator thread is the thread corresponding to the thread gauge.

Notes: 
1.Clean the threads before testing; 
2.Go and no-go gauges must be screwed in vertically and with slight force, and cannot be screwed in by force; 
3.Go and no-go gauges must be calibrated regularly.

二．The steps to determine the thread type using a caliper and a thread gauge are as follows:

1. Measure the outer diameter (for external threads) or inner diameter (for internal threads) of the thread

External thread: Use a caliper to measure the major diameter of the thread (the outermost diameter). 
Internal thread: Measure the minor diameter of the thread (the diameter inside the thread). 
Note: When measuring, avoid the worn part of the thread crest and take the average value of multiple measurements.

   
2. Measure the thread pitch (threads per inch or mm)

Match the teeth of the gauge with the thread grooves one by one to find the teeth that fit perfectly.
Read the pitch marked on the teeth:
Metric thread: directly display the pitch (such as 1.5mm, 2mm, etc.).
Inch thread: display the number of teeth per inch (such as 11 teeth/inch, 14 teeth/inch, etc.).
Alternative method (when there is no gauge):
Use a caliper to measure the distance of 10 teeth and divide it by 10 to get the average pitch (applicable to metric threads).
For imperial threads, count the number of teeth within 1 inch.

3. Check thread parameters

Check the standard manual: compare the measured diameter and pitch with the thread standard table.
For example:
Measured outer diameter ≈ 17.9mm, pitch 1.5mm → M18×1.5.
Measured inner diameter ≈ 18.8mm, 14 threads per inch → G1/2.

Notes
1. The old thread may be worn, so the unworn part should be selected for measurement.