Do I Need a Backflow Preventer for an Espresso Machine?

If you are plumbing a commercial espresso machine into a building water line in the United States, check the adopted plumbing code before choosing its backflow protection. Section 608.17.1.2 of the 2018 International Plumbing Code, as quoted by ASPE, names coffee machines and accepts ASSE 1022 or ASSE 1024 protection, or an air gap. The Maryland Plumbing Code 2024 text on UpCodes adds ASSE 1032. Which edition governs your installation depends on local adoption.

For most single-machine cafes on a non-carbonated line, start the discussion with an ASSE 1022 vented dual check matched to the machine’s fittings: Anderson Brass ABF-1LL, ABF-1FLL for flare x flare, or Watts SD3-MF if you want a strainer. If a carbonator shares the supply, ASSE 1022 is the vented category ASSE’s scope and Anderson Brass tie to carbonated equipment; confirm the required arrangement with your plumber. Your plumber and local code adoption decide the final selection, and the Anderson models need the current-certification check noted below.

Jump to the devices.

What a backflow preventer actually is

A beverage backflow preventer protects the potable supply against reverse flow from equipment. Per ASSE International, the dual-check designs in standards 1022, 1024 and 1032 use two independently acting check valves biased to a normally closed position. ASSE 1022 adds a normally open atmospheric port between the checks to discharge liquids or gases during backflow. Materials and connections depend on the model.

A single check valve does not establish compliance with a listed dual-check assembly standard. Check the exact machine manual and device listing rather than assuming an internal valve meets the adopted code. Filtration is a separate function from backflow protection.

What the code says, and where it actually applies

The Maryland Plumbing Code 2024, as shown on UpCodes at Section 608.17.1.2, requires backflow protection at each coffee-machine and noncarbonated-beverage-dispenser water supply connection using ASSE 1022, ASSE 1024 or ASSE 1032, or an air gap. ASPE’s June 2, 2022 Pipeline article quotes the 2018 International Plumbing Code at the same section number: that edition lists ASSE 1022 or ASSE 1024, or an air gap.

The edition matters: ASSE 1032 is an option in the Maryland 2024 text, but is not named in the 2018 IPC provision quoted by ASPE. Neither text establishes which rules govern your address.

What about the ice machine?

Section 608.17.1.2 in the two named texts covers coffee machines and noncarbonated beverage dispensers; it does not name ice machines. That limited scope does not establish whether an ice machine needs backflow protection.

For sizing and selection, see our guide to how big an ice machine a coffee shop needs.

Why the rule exists

EPA’s Potential Contamination Due to Cross-Connections and Backflow Prevention describes two mechanisms. Backsiphonage can occur when supply pressure falls, including during a main break, firefighting draw or high demand. Backpressure occurs when downstream pressure exceeds supply pressure. Chemicals or stagnant water could enter a potable line through an unprotected cross-connection; that is a conditional hazard, not evidence of contamination in a particular espresso machine.

Carbonated equipment introduces a CO2 backpressure concern. Anderson Brass describes its ASSE 1022 preventers for carbonator systems and explains that the vent can discharge a CO2 and water mixture if fouling or leakage occurs. EPA also identifies thermal expansion as a source of backpressure, so it belongs in the installation discussion.

EPA reports a Monterey, California courthouse incident in which sodium nitrate from the boiler/cooler system entered drinking water through a faulty backflow device. Nineteen people became sick after drinking coffee made with that water. This was a boiler/cooler incident, not an espresso-machine failure. The paper’s cover reads September 27, 2001, and its body header reads August 13, 2002.

ASSE 1022 vs 1024 vs 1032: which one your machine needs

All three standards appear in the Maryland 2024 text of Section 608.17.1.2; the 2018 IPC provision quoted by ASPE names 1022 and 1024. Both allow an air gap. The standards have different scopes, so code acceptance and equipment suitability both matter.

Standard	Title / scope per ASSE International	Vent	Practical consequence
ASSE 1022	Beverage backflow protection engineered for carbonated post-mix equipment; continuous or intermittent pressure	Normally open atmospheric port between two normally closed checks	Per ASPE, downstream-check failure can cause discharge; provide indirect drainage to a safe discharge point.
ASSE 1024	Dual-check protection for low-hazard pollution at residential service lines and individual outlets	No vent, per ASPE	No drain required per ASPE; respect the low-hazard scope and maker’s temperature limits for hot-water use.
ASSE 1032	Dual-check protection for carbonated post-mix and noncarbonated beverage dispensers against returning CO2 gas and carbonated water	ASSE’s scope does not specify an atmospheric port	Check the exact device design; the scope’s omission does not establish that every model is unvented.

Per ASSE, these scopes use two independent normally closed checks under continuous or intermittent pressure. ASSE 1024 covers cold-water service, with hot-water use limited by the manufacturer’s temperature specification. Have your plumber match the hazard, equipment, drainage and locally accepted standard to the device.

A vent discharge deserves attention, but a drip alone does not diagnose its cause. ASPE describes downstream-check failure as one discharge condition; use the exact model’s troubleshooting instructions and have your plumber assess the device.

The filter myth, corrected

Check the exact filter or manifold documentation for any claimed backflow listing. Filtration performance and a shut-off function do not by themselves establish compliance with the backflow standard your installation requires.

For water treatment, see our water filtration guide for commercial espresso machines.

Two authorities to check: plumbing and food safety

Ask your local plumbing authority about the adopted plumbing code, permits and inspections for the proposed connection. Ask your health department which food-code edition and amendments apply to your cafe. These are two authorities to check, not a universal inspection schedule.

The FDA Food Code 2022 addresses point-of-use backflow protection in Section 5-203.14 through an air gap under Section 5-202.13 or an approved device under Section 5-202.14. Section 5-202.13 specifies an air gap at least twice the inlet diameter and no less than 1 inch. Section 5-202.14 calls for the applicable ASSE standard for the specific application and device type, including construction, installation, maintenance, inspection and testing.

FDA offers the Food Code as a model for government adoption. Your local adopted text determines its application. Ask your water utility whether additional cross-connection requirements apply; do not assume every small dual-check device has the same registration or testing obligations.

Devices you can actually buy

Device	ASSE standard (per maker)	Vented	Inlet x outlet fittings	Strainer	Where to buy	Best for
Anderson Brass ABF-1LL	1022; certificate caveat below	Yes	3/8 in MNPT x 3/8 in flare	Not stated by maker	Amazon: Parts Pantry	A specified MNPT-to-flare connection
Anderson Brass ABF-1FLL	1022; certificate caveat below	Yes	3/8 in flare x 3/8 in flare	Not stated by maker	Amazon: Parts Pantry	A specified flare-to-flare connection
Watts SD3-MF 3/8	1022	Yes	3/8 in female NPT x 3/8 in SAE male flare	Wye strainer	Amazon: LNA Enterprises	A vented configuration with a strainer
Watts SD2-MF 3/8	1032	Not stated by maker	3/8 in SAE male flare x 3/8 in SAE male flare	Conflicting maker statements; confirm with Watts	Amazon: Homestead Decor	An accepted ASSE 1032 flare-to-flare application
Multiplex 19-0897	1022	Not stated by maker	Not stated by maker	Not stated by maker	Foodservice parts dealers	An exact replacement specified by your equipment supplier
Vista VersaCheck	1024 / 1032	Not stated by maker	1/4 in FNPT x FNPT or 3/8 in FNPT x FNPT; aluminum or PVC	Not stated by maker	Vista Water Group direct	A specified FNPT connection under an accepted standard

Amazon offers and sellers below are as of October 2026, per the respective Amazon listings; availability can change. Specifications in the table are per Anderson Brass, Watts, Welbilt’s Multiplex parts book and Vista Water Group. Confirm the exact model and fittings before ordering.

The Amazon product cards below are affiliate links; we may earn a commission at no extra cost to you. FranchiseFeast is a participant in the Amazon Associates Program. As an Amazon Associate I earn from qualifying purchases.

Vented MNPT-to-flare option

Anderson Brass ABF-1LL ASSE 1022 Vented Dual Check Backflow Preventer

Standard / vent

ASSE 1022, vented, per Anderson Brass

Connections

3/8 in MNPT inlet x 3/8 in flare outlet, per Anderson Brass

Construction

Lead-free brass body and stainless steel discharge retainer, per Anderson Brass

Match these fittings to the specified connection and plan the vent discharge with your plumber. Anderson's maker-hosted ASSE 1022-2017 certificate shows an expiration of June 30, 2026. Confirm current certification with Anderson or the IAPMO/ASSE listing before installation. As of October 2026, listed in stock on Amazon, sold by Parts Pantry.

Specs: Anderson Brass product page and certificate; Amazon listing

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Same ABF family, different fittings: flare x flare

Anderson Brass ABF-1FLL ASSE 1022 Backflow Preventer, Flare x Flare

Standard / vent

ASSE 1022, vented, per Anderson Brass

Connections

3/8 in flare inlet x 3/8 in flare outlet, per Anderson Brass

Construction

Lead-free brass body and stainless steel discharge retainer, per Anderson Brass

Choose this fitting pair only when it matches the planned connection. Anderson's maker-hosted ASSE 1022-2017 certificate shows an expiration of June 30, 2026. Confirm current certification with Anderson or the IAPMO/ASSE listing before installation. As of October 2026, listed in stock on Amazon, sold by Parts Pantry.

Specs: Anderson Brass product page and certificate; Amazon listing

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Vented ASSE 1022 option with a wye strainer

Watts SD3-MF 3/8 Dual Check Backflow Preventer with Wye Strainer

Model

SD3-MF 3/8, order code 0061657, per Watts

Standard / vent

ASSE 1022 with atmospheric vent, per Watts

Connections

3/8 in female NPT inlet x 3/8 in SAE male flare outlet, per Watts

Features

Wye strainer; lead-free, per Watts

This is the strainer-equipped SD3-MF configuration, not the SD3-MF-LS variant. As of October 2026, the matching FPT x SAE configuration is listed in stock on Amazon, sold by LNA Enterprises. Confirm order code 0061657 with the seller before ordering.

Specs: Watts SD-3 specification sheet; Amazon listing

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ASSE 1032 dual check with SAE male flare ends

Watts SD2-MF 3/8 Dual Check Backflow Preventer, Flare x Flare

Model

SD2-MF 3/8, order code 0061655, per Watts

Standard

ASSE 1032, per Watts

Connections

3/8 in SAE male flare x 3/8 in SAE male flare, per Watts

Lead-free

Yes, per Watts

ASSE 1032 appears in the Maryland 2024 provision, but not the 2018 IPC text quoted by ASPE. Confirm local acceptance. Watts' page does not state a vent, and its strainer statements conflict; confirm the configuration with Watts. As of October 2026, listed in stock on Amazon, sold by Homestead Decor.

Specs: Watts SD-2 specification sheet and SD2-MF product page; Amazon listing

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Welbilt’s Multiplex parts book identifies 19-0897 as an ASSE 1022 assembly. Buy through foodservice parts dealers such as WebstaurantStore; its listing is a secondary dealer source, not maker confirmation of specifications. Exact-model vent, fittings, strainer and lead-free status are not stated in the parts book, so confirm those details and availability with the dealer.

Per Vista Water Group, VersaCheck beverage models meet ASSE 1024/1032 and use lead-free materials. Four FNPT variants pair 1/4-inch ends (VCB025-A aluminum or VCB025-P PVC) or 3/8-inch ends (VCB038-A aluminum or VCB038-P PVC). As of October 2026, Vista offers them directly as single units or cases of 12. Vista does not state an explicit vent or built-in-strainer specification; its instructions recommend an upstream screened strainer where source water contains debris. Confirm the model and availability with Vista.

The supply line itself

Choose a factory length and follow the connector manufacturer’s installation instructions. The machine-side connection is model-specific: La Marzocco’s GB5/FB80 manual specifies 3/8-inch compression for the USA and Canada and a BSP connection for the other stated configuration. Check your exact machine’s manual and supplied hose or adapters; a 3/8-inch size alone does not make compression, flare, NPT and BSP interchangeable.

Longer factory-length connector with female compression ends

LASCO 10-0962 Braided Stainless Steel Supply Line, 36 in

Length

36 inches, per LASCO

Connections

3/8 in female compression x 3/8 in female compression, per LASCO catalog

Construction

Stainless-steel braid; low-lead, per LASCO

Use only where both compression ends match the specified connections. As of October 2026, listed in stock on Amazon, sold by Hearthshire.

Specs: LASCO product page and catalog; Amazon listing

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Short male-to-female compression extension

LASCO 10-0512 Braided Stainless Steel Supply Line, 12 in

Length

12 inches, per LASCO

Connections

3/8 in male compression x 3/8 in female compression, per LASCO

Working pressure

125 PSI, per LASCO current product page

Construction

Stainless-steel braid; low-lead, per LASCO

This is an extension with one male and one female compression end, not a connector with two female ends. Match it to the planned supply connection and machine instructions. As of October 2026, listed in stock on Amazon, sold by Amazon.com.

Specs: LASCO product page; Amazon listing

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What buying a device does and does not settle

A device’s stated standard is only part of the selection. Ask your plumber which model, fittings and vent-drain arrangement suit the machine and adopted code. Ask the plumbing authority about permits and inspections, the water utility about applicable cross-connection rules, and the health department about its adopted food code. Use the machine and device manuals for installation and maintenance requirements rather than assuming a universal testing schedule.

If you are still selecting the machine itself, see our commercial espresso machine guide and coffee shop equipment list. For water treatment, see water filtration for a commercial espresso machine. Fold plumbing costs into your opening budget with our coffee shop startup cost calculator, and explore the cafe equipment hub for related equipment. If a point-of-use heater will feed your brewer, see our small coffee shop water heater sizing guide.