Guide · Foam cannons
Foam cannon orifices: 1.1 vs 1.25 mm and electric washers
Foam cannons often ship with a 1.25 mm orifice fitted and a 1.1 mm in the box. What MJJC, MTM Hydro and Active say, and why Active's rule is for its own machine.
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Picks that fit
- MJJC Foam Cannon S V3.0 with 1/4 in quick connector adapter (QRFLSV3)Check price on Amazon
- MJJC Foam Cannon PRO V3.0 with 1/4 in quick connector adapter (QRFLPROV3)Check price on Amazon
- SIMPSON 80271 high pressure foam cannon, 1 L, 1/4 in QC plug, 1,600‑4,000 PSICheck price on Amazon
Short answer
Some foam cannons ship with a 1.25 mm orifice fitted and a 1.1 mm orifice in the box: MJJC's S V3.0 and MTM Hydro's PF22.2 both do. Use the one your machine's maker or the cannon's maker specifies. Active says its Active 2.0 needs 1.25 mm or larger; that rule is for the Active 2.0 only, not for every electric washer.
Picks that fitAll picks and how to choose
What ships in the box
- MJJC's Foam Cannon S V3.0 with 1/4 in quick connector (SKU QRFLSV3) comes with a 1.25 mm orifice installed and a 1.1 mm orifice included in the package.[1]
- MTM Hydro's PF22.2 (SKU 14.5013) ships with a 1.25 mm orifice installed and a 1.1 mm orifice in the kit.[2]
The orifice is a small insert where water enters the cannon. It works like a nozzle: it restricts the flow from your machine.
Orifice sizes and nozzle sizes
MTM Hydro labels its 1.25 mm orifice as size 3.5 and its 1.1 mm orifice as size 3.0.[2] Those are the same size numbers used for spray tips. Cat Pumps explains that a nozzle number is the nozzle's flow in GPM at 4,000 PSI.[3] So, by MTM's labels, swapping from 1.25 mm to 1.1 mm moves the cannon from a size 3.5 restriction to a smaller size 3.0 one.
| Orifice | MTM's size label | Size page |
|---|---|---|
| 1.25 mm | 3.5 | Size 3.5 |
| 1.1 mm | 3.0 | Size 3.0 |
Cat Pumps and General Pump publish the formula that links size, flow and pressure: nozzle number = GPM x √(4,000 / PSI).[4] A smaller number on the same flow means a tighter restriction. The nozzle size chart and which nozzle size fits your machine show how to compare a size with your machine's rated output.
MJJC's S V3.0 page gives the orifices in millimeters; we have no MJJC statement that maps them to size numbers, so MTM's labels apply to MTM's parts.
Active's guidance, for the Active 2.0 only
Active's guide for its Active 2.0 electric pressure washer says to use foam cannon orifices of 1.25 mm or larger, because a smaller orifice can cause excessive current draw that may damage the motor.[5] On an Active 2.0, the 1.1 mm orifice that MJJC and MTM include is below Active's minimum. Keep the 1.25 mm one fitted.
Active also says the Active 2.0 ships with size 3.7 nozzles and recommends nozzle sizes from 3.5 to 5.0 for that machine.[5] A 1.25 mm orifice, which MTM labels size 3.5, sits at the bottom of that range.
This is machine-specific advice. Active does not speak for other brands, and we do not turn its rule into one for all electric washers. If your machine's manual or maker names an orifice or nozzle range, follow it. If it does not, ask the maker before fitting the smaller orifice.
The cannon's own rating
The orifice is one limit; the cannon's pressure rating is another. MTM Hydro's foam-cannon page lists the PF22.2 at 1,100 to 5,000 PSI.[6] Keep your machine's pressure inside the rating of the cannon you buy.
What we do not cover
We cover foam cannons as hardware only. We give no advice on soaps, products, dilution or ratios, and we make no claims about foam thickness or cleaning results.
Approved foam cannons
Picks that fit3 products
All three are 1/4 in quick-connect versions. MJJC S V3.0 (QRFLSV3) ships with the 1.25 mm orifice fitted and a 1.1 mm spare.
More on choosing
For the MJJC PRO V3.0 and SIMPSON 80271, check the maker's page for the orifice supplied. On an Active 2.0, keep a 1.25 mm or larger orifice fitted. The MJJC listings include a soap sample; we cover the hardware only. On Amazon, check that Ships from / Sold by is Amazon.com or the brand.
1/4 in quick connector cannon with two orifices
MJJC Foam Cannon S V3.0 with 1/4 in quick connector adapter (QRFLSV3)
1/4 in quick connector version of MJJC's larger cannon
MJJC Foam Cannon PRO V3.0 with 1/4 in quick connector adapter (QRFLPROV3)
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Questions
Should I use the 1.1 mm orifice on an electric pressure washer?
Only if your machine's maker allows it. Active says its Active 2.0 needs foam cannon orifices of 1.25 mm or larger, because a smaller one can cause excessive current draw that may damage the motor. That is Active's rule for its own machine; check your maker's guidance.[5]
What orifice comes with a foam cannon?
It depends on the model. MJJC's S V3.0 (QRFLSV3) and MTM Hydro's PF22.2 both ship with a 1.25 mm orifice installed and a 1.1 mm orifice in the box.[1][2]
Is a foam cannon orifice the same as a nozzle size?
MTM Hydro labels them that way: its 1.25 mm orifice as size 3.5 and its 1.1 mm as size 3.0. Nozzle size numbers are flow in GPM at 4,000 PSI, per Cat Pumps.[2][3]
What pressure is a foam cannon rated for?
Per model. MTM Hydro's foam-cannon page lists the PF22.2 at 1,100 to 5,000 PSI. Keep your machine's pressure inside the cannon's rating.[6]