Preparing for your test
(a visual guide with quick tips to help you prepare for our visit)
Over the years, many of you have asked us questions about your backflow assembly. What does it looks like? Where is it installed? Am I ready for testing? Knowledge is power (and a picture is worth a thousand words!), so we've created this visual guide to help you understand your equipment and prepare for our visit.
This guide is intended primarily for those of you with assemblies on residential irrigation systems, but a lot of the info here is also applicable to other testing jobs. The four most important things to keep in mind are that we need equipment to be readily visible, accessible, and operable, with water available for testing. If it's not, we may be unable to complete our work, or we may need to bill for additional parts or services. Most of our testing is done as a drop-in service, and service calls are non-refundable, so please make sure things are ready to go before your order, or contact us if you need extra time to prepare. You can click on any photo below for an enlarged image.
Our photo gallery has lots of extra helpful info if you'd like to take a deeper dive. When in doubt, give us a call - we'd be happy to help! We'd also like to include a reminder that the policies in our FAQ and Terms of Service apply to all orders, and that this guide is not intended to replace them.
This guide is intended primarily for those of you with assemblies on residential irrigation systems, but a lot of the info here is also applicable to other testing jobs. The four most important things to keep in mind are that we need equipment to be readily visible, accessible, and operable, with water available for testing. If it's not, we may be unable to complete our work, or we may need to bill for additional parts or services. Most of our testing is done as a drop-in service, and service calls are non-refundable, so please make sure things are ready to go before your order, or contact us if you need extra time to prepare. You can click on any photo below for an enlarged image.
Our photo gallery has lots of extra helpful info if you'd like to take a deeper dive. When in doubt, give us a call - we'd be happy to help! We'd also like to include a reminder that the policies in our FAQ and Terms of Service apply to all orders, and that this guide is not intended to replace them.
visibILITY
When we visit, we need to be able to promptly locate and identify your equipment. Please make sure valve boxes for the backflow assembly AND any upstream shutoff valves are 100% visible, with the equipment inside fully exposed once the box is opened. Plants, landscape materials, trash bins, etc. should be cleared from the lids, and any soil or other debris in the box (with the exception of easily removable/replaceable insulation) should be removed for a clear view of the equipment inside. Your water district reminder will usually list the location of your backflow assembly, but feel free to contact us if you need this information.
☝ Above: the most common valve box arrangement is an upstream shutoff (round box) next to a backflow assembly (rectangular box). Sometimes, the round box is located further away, or may be absent (especially if the upstream shutoff is absent or installed inside the backflow box).
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Please make sure any buried or covered lids are cleared off. (This installation does not have a separate upstream shutoff box.)
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Here are a few common models of backflow assembly, so you can see the type of equipment we're looking for:
Model: Wilkins 950XLT
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Model: Wilkins 350
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Model: Febco 850
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Note: valve boxes may contain other equipment (like the zone control valves below) that we do NOT need access to, so please make sure the correct box is exposed.
ACCESSibility
If your equipment is visible as shown above, you've probably got a good head start on this one. We want to make sure we can promptly access your equipment and freely move about the work area as we test. Some common access barriers are:
- Gates and fencing: please use the order comments to notify us about any locks, tricky gate latches, pets in the work area, gate codes, or anything else that might prevent us from easily accessing your equipment.
- Items (plants, trash bins, etc.) crowding or covering valve boxes: we need room to kneel in front of valve boxes, freely move over/around them, and place our equipment. Please provide a clear path to the work area, plus clear space of about two feet around the box edges and four feet above this general work zone - any vegetation remaining in these areas may be pruned or otherwise impacted during testing.
- Buried box lids or equipment: valve boxes covered by (or filled with) debris like soil or bark dust can prevent us from accessing your valves. Please clear lids off and make sure we have a few inches clear space below the equipment inside.
- Flooded boxes: if the equipment in your boxes is partially or completely covered with water, please let us know. Depending on how persistent the issue is, and the resulting condition of the equipment, we may want to schedule your service for a drier time of year, or in some cases may decline testing.
OPERABILITY
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We need to operate TWO shutoff valves and FOUR test ports on most backflow assemblies. If the irrigation system is turned off, we'll likely also need to use the upstream shutoff valve (examples here). If you can't operate these valves, there's a good chance we won't be able to either. Use of these valves can be compromised by:
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Clearance guidelines
To ensure have have enough space to test your assembly, we'll need a minimum of 3" clear space around all handle surfaces, and 4" clear space around all test port surfaces. The photos below provide examples.
3" around handles (shown being operated with valve handle wrench)
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4" around test ports (shown being operated with screwdriver). This assembly is installed with the test ports facing up (ideal).
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4" around test ports (shown with adapters and gauge attached). This assembly is installed on its side, with test ports facing the side of the box, which often leads to reduced clearances.
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It's also important to make sure there's some space below your equipment. If soil, roots, rocks, or other debris are making contact, we may have trouble operating shutoff valves and test ports. Code is 12" clear space below your equipment, though 4-8" is usually sufficient for most testing and repair work.
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Valve condition
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Our ability to operate a shutoff valve depends mainly on the condition of the handle and the stem it's mounted to - if these aren't in sound operating condition, we may not be able to complete your test or put valves back in their original positions afterward. The shutoff valves shown here have been removed from assemblies taken out of service. They show the range of handle conditions we see in the field, from like new to progressive stages of disrepair caused by corrosion and valve stem weakness. If your shutoff valves resemble items 2-7, please contact us before your order.
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Test port valves can also seize up (or be worn, or damaged from freezing), but this is an issue we can usually address during your test by replacing the test cock and continuing with our work. There are some other problems (like seized valves) that aren't visible to the naked eye and only become apparent when somebody tries to operate the valve.
Water Availability
Testing requires water pressure of at least 15 PSI. If your irrigation system is turned off for the season, we'll need the shutoff valves on your backflow assembly and upstream to be readily visible, accessible, and operable before our drop-in visit, with the piping serving your backflow assembly connected and undamaged. Otherwise, please ensure water is on to your assembly before we visit. Please note that we DO NOT operate water meter valves or other municipally-owned shutoffs, so these need to be on before your order is placed.