Sub Zero Covers
Small green insulated backflow cover seated on river-rock landscaping beside a road, carrying the Sub Zero Covers product tag.
Small assembly cover on a landscaped median

By assembly and size

1½" PVB backflow cover

1½" PVB backflow cover sizing starts with the assembly on the tag. At 1½", 4 PVB assemblies from the brands we pattern for are common: Watts 800M4 / LF800M4, Febco 765 / 765U, Zurn Wilkins 720A, and Apollo / Conbraco PVB4A / PVBLF4A. The price list maps this pipe size to 3 stock covers, and the published dimensions below say which one to pull.

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What "1½" PVB" covers on a counter

Pressure vacuum breaker. At 1½" the assemblies your customers bring in are Watts 800M4 / LF800M4, Febco 765 / 765U, Zurn Wilkins 720A, and Apollo / Conbraco PVB4A / PVBLF4A, all vertical units whose height depends on the riser under them. They are not the same size: the Apollo / Conbraco PVB4A / PVBLF4A is 7.25" wide and the Febco 765 / 765U is 11.5", so "a 1½" PVB" is not a single envelope.

The stock covers for 1½"

The April 2026 price list maps 1½" to 30 × 24 (DS3024), 36 × 24 (DS3624), and 42 × 24 (DS4224). The table below orders them closest fit first for each assembly: the cover should clear the width with room to close at the base.

Measure the install, not the valve

A PVB sits 12" above the highest downstream head, so the riser is most of what you are covering. Measure pad to bonnet and leave the bonnet free to vent.

When to measure instead

Unions, strainers, OS&Y gates, and wall-tight mounts all move an assembly off its spec sheet. If the tag is gone or the install is odd, measure it or send photos for a custom cover. For the type as a whole see PVB covers; for another size, start at the fitment hub.

Sub Zero Covers sells through distributors only. Distributor accounts see pricing and availability in the portal; everyone else orders through their supply house, or applies for distributor access.

Assemblies at this size

1½" pressure vacuum breaker assemblies and the cover that fits

Dimensions in inches from each manufacturer's spec sheet with standard shutoffs. Width and overall height; add the riser. The cover column is the closest stock fit by published length; confirm against the assembly in front of you.

AssemblyWidthAbove CLBelow CLClosest stock cover
Watts 800M4 / LF800M49.25"3.25"6.25"30 × 24 (DS3024)
Febco 765 / 765U11.5"——30 × 24 (DS3024)
Zurn Wilkins 720A———30 × 24 (DS3024)
Apollo / Conbraco PVB4A / PVBLF4A7.25"——30 × 24 (DS3024)

Common questions

Which cover fits a 1½" PVB?
One of 30 × 24 (DS3024), 36 × 24 (DS3624), and 42 × 24 (DS4224), chosen by the assembly's end-to-end length. The table above names the closest fit for each PVB at this size.
Do all 1½" PVB assemblies take the same cover?
Not always. At this size the published lengths run from 7.25" (Apollo / Conbraco PVB4A / PVBLF4A) to 11.5" (Febco 765 / 765U). Order by model.
Is this a heated enclosure?
No. Sub Zero Covers are insulated, unheated covers (R-13 standard, R-30 extreme weather). They are not ASSE 1060 listed enclosures. Where a spec calls for a Class I heated enclosure, ask sales before quoting.

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