Tom Hempel Backflow Testing LLC

Backflow Basics

What is Backflow?

Drinking water flows from its source to your tap in pressurized water pipes. Typically it only flows in one direction, although under certain circumstances it can flow in the opposite direction, termed "backflow." This can be caused by things such as a water main break, or high demand at a fire hydrant. When backflow occurs, water runs backward through the water system. The water flowing backward often is non-potable and may contaminate the general drinking water supply.

What is Backflow Testing?

The majority of backflow assemblies include a check valve or multiple valves, a set of springs, and occasionally a relief valve. Each of these internal mechanical components must be tested annually and maintained if necessary. During a backflow test, the assembly is pressurized and then each part is isolated to ensure it is operating at an acceptable level. The check valves must hold a minimum pressure to pass the inspection, and the relief valves must open before a certain pressure differential is reached. Repairs must be performed if minimum standards are not met in order to satisfy local and state regulations.

What is a cross connection?

A cross connection is any connection between piping that carries drinking water and the piping that carries non-potable water. In a cross connection, a backflow device is required so the water's taste or odor is not affected and harmful chemicals do not enter the drinking water. Common cross connections include sprinkler and irrigation systems, hot tubs, pools, fire suppression systems, radiant heating systems, boilers, soda fountain machines, and auxiliary water systems (wells). If you have any of circumstances, please call us today. We can help to ensure your water is safe.

Is testing required?

Numerous state regulations require all backflow prevention devices to be tested annually. These devices are required to keep the water that passes through them and into the plumbing system beyond them, from flowing back into the water supply, while protecting the quality and safety of the drinking water system. Just like the individual parts of your car, backflow prevention devices have parts that can break down and wear out. Annual backflow tests can help to ensure the drinking water supplied to your home remains safe. If you're not sure whether your system needs a backflow assembly device or an annual test, please call our trained staff for the answer to your questions.

What is a Backflow Preventer?

A backflow preventer is a device installed in the plumbing system that prevents non-potable (not drinkable) water from mixing with clean drinking water. These devices commonly contain a number of valves that ensure that the stagnant and/or polluted water beyond the backflow preventer can never escape.

Please contact us at 503-390-1961 with any additional questions.

What is Backflow Prevention Service?

Backflow prevention service and inspection is vital to maintaining the quality of drinking water. The backflow preventer at your home or place of business is the only thing standing between your clean drinking water and potentially contaminated or stagnant water in auxiliary systems (such as irrigation systems, fire suppression systems, wells, pools, hot tubs, and boilers).

It is crucial that backflow devices are inspected on a regular basis and receive maintenance as necessary. The state of Oregon requires that each backflow preventer be inspected and pass inspection at least once per year. Your water provider is legally required to enforce this legislation and maintain a high level of compliance throughout their district.

Our service area includes the greater Portland metropolitan area, Salem/Keizer and outlying communities of Northwest Oregon. Click here to view our list of communities served. If you would like to know more about backflow prevention service, please contact us with any additional questions.

What Does a Backflow Preventer Look Like and Where is it Located?

Backflow preventers come in many shapes and sizes. The three main categories of backflow assemblies are:

Double Check Backflow Preventers

Double check backflow preventers consist of two check valves, four test ports, and two shut-offs and are commonly found in green rectangular irrigation boxes at ground level. These are also occasionally installed in crawl spaces, garages, and unfinished basements.

Reduced Pressure Backflow Preventers

Reduced pressure backflow preventers are composed of two check valves, a relief valve assembly, a sensing line, four test ports, and two shut-offs. These are required to be installed above ground - both indoor and outdoor - and sometimes in insulated hot boxes.

Pressure Vacuum Breaker or Spill Resistant Pressure Vacuum Breakers

Pressure vacuum breakers consist of a single check valve, an air inlet, two test ports, and two shut-offs. These devices are required to be installed above grade, and are almost exclusively found outdoors.

Contact Us

Tom Hempel Testing, LLC
PO Box 20271
Keizer, OR 97307
Phone: 503-390-1961
Fax: 503-463-1485
Email: tom@testsbytom.com
LSB# 8372 · CCB# 192917

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