Grease never stops coming. Every fryer, wok range, dish pit, and floor drain in a commercial kitchen sends fats, oils, and grease (FOG) down the line every single service. It cools, it congeals, it clings to the pipe wall — and the line that ran clear last month backs up mid-rush this month. If you run a restaurant, manage a food-service facility, or you're the drain pro who gets the 9 p.m. "we're flooding" call, this page is for you.
Here's how grease actually clogs a line, why cabling and enzymes don't fix it, which nozzles cut and flush FOG, and how a preventive jetting schedule turns emergency callouts into a predictable maintenance line item.
Why Grease Lines Keep Re-Clogging
Grease clogs are different from every other blockage, and that's why they come back. A cable machine bores a hole through the plug — the water drains, everyone relaxes — but the pipe wall is still coated in a hardened layer of FOG. Within days that hole re-closes as fresh grease sticks to the old buildup. You didn't clean the pipe; you drilled a straw through it.
Enzyme and bacteria additives break down some grease over time, but they can't keep up with a busy kitchen's volume, and they do nothing for the calcified layer already welded to the wall. The only thing that actually restores full pipe diameter is high-flow water scouring the wall clean — hydro jetting. A jetter's rear jets peel grease off the pipe wall the whole length of the run and flush it downstream, so the line drains like new instead of like a straw.
New to the method? Start with Kitchen Grease Lines: The Most Profitable Drain Call You Are Not Taking and How to Jet a Kitchen Drain Line: Step-by-Step.
The Two Grease Problems: Kitchen Lines and Floor Drains
Kitchen & grease-trap lines
These are the 2"–4" lines running from the three-compartment sink, dish machine, and mop sink out to the grease interceptor and beyond. They carry the heaviest FOG load in the building and are the most likely to back up during service. Jetting these on a schedule is the single highest-value thing a food-service operator can do for their drains.
Floor drains
Floor drains catch spills, mop water, and everything that misses the sink. They clog with a mix of grease, food solids, and grit, and a backed-up floor drain is an instant health-code problem. They need their own maintenance rhythm — see our Restaurant Floor Drain Maintenance: Complete Playbook for the full routine.
Preventive Jetting vs. the Emergency Call
An emergency backup during dinner service costs a restaurant far more than the plumber's invoice: comped tables, a closed kitchen, health-department exposure, and a soaked dish area. Preventive jetting flips that math. A kitchen line that gets scoured on a regular schedule never reaches the point of failure — and the work happens off-hours, on your calendar, not the pipe's.
For drain pros, this is the difference between one-off panic calls and a recurring maintenance contract with predictable revenue. Our guides on selling recurring jetting services and landing restaurant and HOA contracts walk through how to pitch and price it.
A simple grease-line maintenance cadence
- High-volume kitchens (fryers, wok stations, heavy sauté): jet main grease lines every 30–90 days.
- Moderate-volume kitchens (cafés, bakeries, limited fry): every 3–6 months.
- Floor drains & mop sinks: fold into the same visit; they clog on a similar curve.
- After any backup: jet the full run, not just the plug — then set the calendar so it doesn't happen again.
Cadence depends on menu, volume, and pipe condition. When in doubt, jet, camera the line, and let what you see set the interval.
Choosing a Grease Nozzle
Grease work rewards a specific nozzle design. You want strong rear jets to pull the nozzle down the line and shear grease off the wall, plus a shape that flushes the debris back toward you instead of packing it forward. Raw pressure matters less than jet geometry — that's why an engineered nozzle clears grease in fewer passes than a stamped one. (More on that in Sewer Nozzle Jet Angles Explained.)
Egg nozzles — the grease workhorse
The egg shape rides over debris and directs high-flush rear jets against the pipe wall, making it the go-to for FOG. On typical shop machines (2–20 GPM, 1,500–4,000 PSI, 3/8" or 1/2" hose):
- KEG Egg Nozzle w/ Forward Jet 3/8" — $118.66 — flushes grease while a forward jet opens soft plugs.
- KEG Egg Devastator w/ Forward Jets 3/8" — $118.66 — extra forward cutting for packed grease.
- KEG Egg Devastator Nozzle 1/2" — $270.55 — more flow for bigger kitchen mains on higher-GPM machines.
Cleaning & traction nozzles — wall scouring
- KEG Cleaning Nozzle 3/8" — $372.53 — rear-jet pattern engineered to strip the pipe wall clean.
- KEG Cleaning Nozzle 1/2" — $372.53 — same job, more flow for larger lines.
- KEG Traction Nozzle w/ Forward Jet 3/8" — $343.34 — grips and self-feeds through long or greasy runs.
General flushing
- KEG Sewer Flush Nozzle 3/8" — $75.42 — high-flush finisher to carry loosened grease downstream.
Want it sorted for you? See the full Grease & Drain Lines collection and Grease Clogs, or read The Best Nozzle Configuration for Grease-Packed Lines to match jets to your GPM. Not sure? Our Nozzle Guide matches a nozzle to your machine in about a minute, or call (864) 804-6637.
Grease Kits for Food-Service Accounts
If grease accounts are your bread and butter, a purpose-built kit gets every configuration you'll need in one box:
- Grease Kit 1/2" — $1,899.00 — a grease-focused loadout for 1/2" machines working restaurant mains.
- 1/2" Sewer Jetter Sanitation Kit — $1,799.00 — drain & grease cleaning set for food-service and sanitation routes.
Browse all Plumber Kits and Starter Kits, or filter by hose size: 3/8" nozzles · 1/2" nozzles.
Why Engineered Nozzles Pay Off on Grease Routes
Grease is where cheap nozzles cost you the most. Our nozzles pass through on the first try; cheap nozzles take 3–4 passes — because the jet angles and orifice sizing are engineered, not stamped. On a grease line, three extra passes per drain across a multi-drain restaurant is an hour you don't get back.
These nozzles are built in Germany by KEG Technologies and assembled to order in Spartanburg, SC — engineered & manufactured by KEG Technologies. And they're built to be rebuilt, not thrown away. When the jets wear, you swap the ceramic or steel inserts instead of buying a new nozzle — insert cost per job can run as low as $1.50, at 80%+ jetting efficiency. Replacement inserts ship the same day. Don't change the nozzle, change the inserts.
Every insert is backed by a 5-year ceramic / 3-year steel warranty, included — details on our Warranty page. See the long-term math in Steel vs. Ceramic Inserts.
Frequently Asked Questions
How often should a restaurant jet its grease lines?
It depends on volume and menu. High-volume kitchens with fryers and wok stations often jet every 30–90 days; lighter operations every 3–6 months. Jet, run a camera, and let the pipe condition set your interval.
Why does my kitchen drain keep clogging even after it's snaked?
A cable bores a hole through the grease plug but leaves the pipe wall coated. Fresh grease re-closes that hole fast. Jetting scours the wall back to full diameter, so it drains like new instead of re-clogging in days.
Will jetting damage my kitchen drain pipes?
Used correctly at the right flow, no. Matching GPM/PSI to the line is the whole game — see What GPM and PSI Do I Need? or call us and we'll spec it.
What nozzle is best for grease?
An egg or cleaning nozzle with strong rear jets. The egg shape rides over debris and flushes FOG back toward you; a forward jet opens soft plugs first. See the Grease & Drain Lines collection.
Jetter or snake for grease?
Jetter, nearly every time. A snake punches a hole; a jetter cleans the whole pipe. Full breakdown in Jetter vs. Snake.
Get Grease Under Control
Shop the Grease & Drain Lines collection, build a grease kit, or use the Nozzle Guide to get matched fast. Questions about your kitchen's setup? Call (864) 804-6637 or email sales@jetterprosupply.com — real jetting people, not a call center. Free shipping over $199, 2–3 day delivery nationwide, 30-day returns. Also serving property management and municipal crews.