How To Splice Drain Pipes with Mission Couplings

Save time and trouble with mission couplings.

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Time

1 hour

Complexity

Beginner

Cost

$20-$40

Introduction

Whether you're working with PVC, ABS or cast iron, mission couplings are essential for fitting a section of pipe into an existing run of waste line.

Tools Required

  • 4-in-1 screwdriver
  • Hacksaw

Materials Required

  • Mission coupling
  • PVC or ABS glue
  • Replacement pipe

Installing a Mission Coupling

When repairing a section of pipe in an existing run, don’t try to cement (solvent-weld) all the new couplings. Most drain systems use rigid pipes fairly large in diameter. You can’t flex them enough to slide on that last fitting and get it to seat fully.

Rather than struggle with cement and risk leaks, pros use a “mission” coupling that clamps over the last joint. That flexibility gives you a much better seal overall, and invaluable peace of mind.

What Is a Mission Coupling?

A coupling in a metal sleeve with band clamps that can be tightened to seal pipe joints.

Though a mission coupling costs more than a plastic coupling, it’s worth it. Sometimes pros will even use two mission couplings in tight situations. Be sure to buy couplings with full steel sleeves, and make sure mission couplings meet code requirements in your area.

Project step-by-step (4)

Step 1

Mark cuts

Buy and assemble matching replacement parts. Mark the cutting points on the old drains about 1/2-in. larger than the replacement.

How To Splice Drain Pipes With Mission Couplings Fh05nov 463 05 014 Hsp SseditTMB Studio

Step 2

Remove pipe

Cut the plastic at a right angle using a fine-tooth saw and remove the assembly.

How To Splice Drain Pipes With Mission Couplings Fh05nov 463 05 015 SseditTMB Studio

Step 3

Install new pipe

Slide the mission coupling onto one pipe and cement plastic couplings onto the other two pipes.

How To Splice Drain Pipes With Mission Couplings Fh05nov 463 05 016 SseditTMB Studio

Step 4

Finish up

Center the mission coupling over the third joint and tighten the bands firmly.

And there you have it — you’ve fixed your old drain couplings and made certain that everything is secure. Now you don’t have to worry about leaks or water damage.

How To Splice Drain Pipes With Mission Couplings Fh05nov 463 05 017 SseditTMB Studio