What Size Sewer Jetting Nozzle Do I Need? A Complete Sizing Guide

Nozzle Size Matters More Than You Think

A nozzle that's too small for your machine wastes pressure. A nozzle that's too big starves the jets. Either way, you're leaving performance (and money) on the table.

Here's how to match the right nozzle to your jetter and your pipes.

Step 1: Know Your Connection Size

Your jetter hose has a thread size at the end. That determines which nozzles physically fit your setup:

• 1/4" NPT — Small trailer jetters, sink machines (typically 1,500-2,500 PSI, 1.5-4 GPM)
• 3/8" NPT — Mid-size jetters, the most common for residential plumbing (2,000-4,000 PSI, 4-12 GPM)
• 1/2" NPT — Full-size truck-mount and trailer jetters (3,000-4,000+ PSI, 8-18 GPM)

If you're not sure, check your hose fitting or your jetter's spec sheet. The thread size is usually stamped on the coupling.

Step 2: Match Your GPM

This is where most plumbers get it wrong. Your nozzle's flow rate must match your jetter's GPM output.

Why it matters: A nozzle rated for 12 GPM on a 6 GPM machine won't generate enough thrust to propel through the pipe. A 4 GPM nozzle on a 12 GPM machine creates excessive back-pressure that can damage your pump.

At KEG Pipe Pro, every 3/8" nozzle comes in GPM-specific variants (4, 6, 8, 10, 12 GPM). For 1/4" and 1/2" nozzles, we custom-jet the inserts to your exact GPM — just enter your specs at checkout.

Step 3: Consider Your Pipe Size

Different nozzle sizes are designed for different pipe diameters:

• 1/4" nozzles: Best for 1.5"-4" pipes (kitchen/bathroom drains, small laterals)
• 3/8" nozzles: Best for 2"-6" pipes (residential sewer laterals, floor drains)
• 1/2" nozzles: Best for 4"-8" pipes (main sewer lines, commercial)
• 3/4"-1-1/4" nozzles: Best for 6"-12"+ pipes (municipal, large commercial) — see our Victory Line

Step 4: Factor in Hose Length

Longer hoses mean more friction loss, which reduces effective pressure at the nozzle. A 400-foot hose loses significantly more pressure than a 200-foot hose.

This is why custom jetting matters. When you tell us your hose length and diameter, we calculate the actual pressure at the nozzle (not just what your pump says) and size the inserts accordingly. A nozzle jetted for 300 feet of 3/8" hose is different from one jetted for 150 feet of 1/2" hose — even on the same machine.

Quick Reference: Common Jetter Setups

Still Not Sure?

Add your jetter specs (PSI, GPM, hose length, hose diameter) on any product page and we'll handle the rest. Every nozzle from KEG Pipe Pro is custom-jetted to your exact machine — no guesswork, no wasted performance.