A Step-by-Step Guide on Installing Grooved Couplings

Installation & Precautions

In piping systems, the use of grooved couplings has become increasingly popular due to their numerous advantages. Grooved couplings provide a reliable and flexible connection between grooved pipes, allowing for easy installation, maintenance, and accommodating for movements and misalignments. Whether you’re working on a plumbing project or an industrial application, understanding how to properly install grooved couplings is essential. In this article, we will provide you with a step-by-step guide that covers the key aspects of installing grooved couplings, ensuring a secure and efficient piping system.

Here is a step by step guide diaphragm: ( View Video)

A detail of grooved pipe.
Step 1

Check whether the groove meets the standard before installation.

Remove the burrs, rust, oil, paint and other impurities on the tube and sealing ring. Pipe ends must be clean and smooth, free from unevenness.

A rubber sealing ring and the grooved pipes.
Step 2

Apply silicone lubricant to the end of pipe, outer surface of rubber ring and sealing lip, and do not use petroleum-based lubricant.

The rubber sealing ring is installed on the steel pipe.
Step 3

Install the rubber sealing ring into the sealing part of a steel pipe.

The two steel pipes are aligned.
Step 4

Align the two steel pipes.

The two steel pipes are aligned.
Step 5

After the two steel pipes are aligned, pull back the rubber ring to the center of the pipe end, so that the rubber ring is just located at the sealing part outside the groove, and ensure that the rubber ring stretches naturally without distortion.

The grooved couplings are installed on the short pipes.
Step 6

Make sure that the grooved couplings are aligned with the grooves on both sides.

The bolt and nut are installed on the grooved coupling.
Step 7

Thread the bolts and nuts.

The grooved coupling is firmly fastened on the pipes.
Step 8

Tighten the nuts evenly from both sides with a torque wrench until the pipe clamp is tightly fastened to the pipe. The gap at the rigid joint must be equal on both sides, and there is no gap at the grooved joint. Rubber rings should not be seen from the outside of rigid and grooved joint.


  • For cut grooved pipes or roll grooved pipes, specifications are based on groove diameter, the groove depth is just a reference dimensions.
  • Before installation, please ensure that the outer diameter of the pipe reaches the standard value or above. If the outer diameter of the pipe is lower than the standard value, water leakage will easily occur.
  • To achieve the best performance, proper bolt torque is required. Excessive torque will damage the clamp and bolts, causing the pipe connection to fall off, causing heavy property loss and serious personal injury!

Description of pressure rating:

  • S30 series 0–600 PSI
  • S80 series 0–1200 PSI
  • S160 series 0–2322 PSI

*Special note: when used at the outlet of high-pressure pumps and plunger pumps, models with one grade higher than the operating pressure must be selected.
(For example: If the actual pressure at the pump outlet is 1200 psi (S80), it is recommended to choose the clamp of the S160 series)

Notes on installation of grooved short pipes

A grooved pipe structure introduction.

Grooved pipes structure

A correct and three error view of grooved coupling installation

Correct and Three Error View

Breaking Torque Table for Austenitic Stainless Steel Bolts and Screws (M1.6-M16)
Thread Breaking Torque (Nm)
Performance Level
50 70 80
M1.6 0.15 0.2 0.24
M2 0.3 0.4 0.48
M2.5 0.6 0.9 0.96
M3 1.1 1.6 1.8
M4 2.7 3.8 4.3
M5 5.5 7.8 8.8
M6 9.3 13 15
M8 23 32 37
M10 46 65 74
M12 80 110 130
M16 210 290 330