Common Questions and Answers of Backflow Testing

ANSWER : A cross-connection is any temporary or permanent connection between a public water system or consumer's potable (i.e., drinking) water system and any source or system containing nonpotable water or other substances. An example is the piping between a public water system or consumer's potable water system and an auxiliary water system, cooling system, or irrigation system. 
ANSWER : Backflow is the undesirable reversal of flow of non-potable water or other substances through a cross-connection and into the piping of a public water system or consumer's potable water system. There are two types of backflow: backpressure backflow and backsiphonage.
ANSWER : Backsiphonage is backflow caused by a negative pressure (i.e., a vacuum ~ or partial vacuum) in a Public water system or consumer's potable water system. The effect is similar to drinking water through a straw. Backsiphonage can occur when there is a stoppage of water supply due to nearby fire fighting, a break in a water main, etc.
ANSWER : Backflow into a public water system can pollute or contaminate the water in that system (i.e., backflow into a public water system can make the water in that system unusable or unsafe to drink), and each water supplier has a responsibility to provide water that is usable and safe to drink under all foreseeable circumstances. Furthermore, consumers generally have absolute faith that water delivered to them through a public water system is always safe to drink. For these reasons, each water supplier must take reasonable precautions to protect its public water system against backflow.

ANSWER : Water suppliers usually do not have the authority or capability to repeatedly inspect every consumer's premises for cross-connections and backflow protection. Alteratively, each water supplier should ensure that a proper backflow preventer is installed and maintained at the water service connection to each system or premises that poses a significant hazard to the public water system. Generally, this would include the water service connection to each dedicated fire protection system or irrigation piping system and the water service connection to each of the following types of premises:

  1. premises with an auxiliary or reclaimed water system:
  2. industrial, medical, laboratory, marine or other facilities where objectionable substances are handled in a way that could cause pollution or contamination of the public water system;
  3. premises exempt from the State Plumbing Code and premises where an internal backflow preventer required under the State Plumbing Code is not properly installed or maintained;
  4. classified or restricted facilities; and
  5. tall buildings.

Each water supplier should also ensure that a proper backflow preventer is installed and maintained at each water loading station owned or operated by the water supplier.

ANSWER : A backflow preventer is a means or mechanism to prevent backflow. The basic means of preventing backflow is an air gap, which either eliminates a cross-connection or provides a barrier to backflow. The basic mechanism for preventing backflow is a mechanical backflow preventer, which provides a physical barrier to backflow. The principal types of mechanical backflow preventer are the reduced-pressure principle assembly, the pressure vacuum breaker assembly, and the double check valve assembly. A secondary type of mechanical backflow preventer is the residential dual check valve.
ANSWER : An air gap is a vertical, physical separation between the end of a water supply outlet and the flood-level rim of a receiving vessel. This separation must be at least twice the diameter of the water supply outlet and never less than one inch. An air gap is considered the maximum protection available against backpressure backflow or backsiphonage but is not always practical and can easily be bypassed.


ANSWER : An RP is a mechanical backflow preventer that consists of two independently acting, spring-loaded check valves with a hydraulically operating, mechanically independent, spring-loaded pressure differential relief valve between the check valves and below the first check valve. It includes shutoff valves at each end of the assembly and is equipped with test cocks. An RP is effective against backpressure backflow and backsiphonage and may be used to isolate health or nonhealth hazards.


ANSWER : A PVB is a mechanical backflow preventer that consists of an independently acting, spring-loaded check valve and an independently acting, spring-loaded, air inlet valve on the discharge side of the check valve. It includes shutoff valves at each end of the assembly and is eqipped with test cocks. The PVB may be used to isolate health or nonhealth hazards but is effective against backsiphonage only


ANSWER : A DC is a mechanical backflow preventer that consists of two independently acting, spring-loaded check valves. It includes shutoff valves at each end of the assembly and is equipped with test cocks. A DC is effective against backpressure backflow and backsiphonage but should be used to isolate only non-health hazards.


ANSWER : An assembly containing an independently operating internally loaded check valve and independently operating loaded air inlet valve located on the discharge side of the check valve. The assembly is to be equipped with a properly located resilient seated test cock, a properly located bleed/vent port, and tightly closing resilient seated shutoff valves attached at each end of the assembly.


ANSWER : Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested with properly calibrated gauge equipment.
ANSWER : One excellent reference manual is the ninth (1993) edition of the University of Southern California's Manual of Cross-Connection Control, which is available from the Foundation for Cross- Connection Control and Hydraulic Research; University of Southern California; KAP-200 University Park MC-2531; Los Angeles, California 90089-2531; 213/740-2032; Another excellent reference manual is the second (1990) edition of the American Water Works Association's (AWWA's) Manual M14, Recommended Practice for Backflow Prevention and Cross-Connection Control, which is available from the AWWA Bookstore; 6666 West Quincy Avenue; Denver, Colorado 80235; 800/926-7337; Most information on this page is from the American Backflow Prevention Association and is a great resource; (877) 227-2127;

Fire Alarm System FAQ's

ANSWER : Yes. According to the NFPA 72 (National Fire Alarm and Signaling Code book) states that all Fire Alarm systems shall be tested annually.
ANSWER : During a fire alarm inspection, some of the things we will do are:check the panel for any supervisory or trouble signals, test all smoke and heat detectors, activate all manual pull stations, activate all audio/visual components, and load test the batteries, all in accordance with NFPA 72.
ANSWER : In the event of a power loss or outage, batteries act as a secondary/standby power supply which will keep your fire alarm system operating. Most batteries are suggested by the manufacturer to be replaced after 3-5 years from the manufacture date. The batteries are to be tested annually with a battery load tester.
ANSWER : Yes. Fire sprinkler systems are highly effective for fire protection once a fire has already started. Fire alarm systems, especially smoke detectors, have the ability to detect smoke and other gases before the flames start. This can give occupants extra time to escape the building. Fire alarm systems can also automatically notify the fire department, saving you valuable time that could save your building and its contents.
ANSWER : Carbon monoxide is a colorless, odorless gas that is produced by certain gas-powered appliances and engines. If a gas leak occurs, carbon monoxide can build up in certain areas. If a person is exposed to the gas for an extended period of time, they can suffer serious complications up to and including death. For this reason, many residential and commercial buildings have carbon monoxide detectors installed to prevent injury or death to occupants.
ANSWER : Different types of buildings are at risk for different types of fires. For example, restaurants are at risk of grease fires or other accidents in the kitchen. Fires that start in apartments or homes are often caused by smoking materials, electrical and heating appliances, and candles.

Fire Extinguisher Questions & Answers

ANSWER : Bottom line: the number of fire extinguishers your building needs to be both safe and up to code will depend on many details about your building, what it contains, and its primary function. At minimum, NFPA dictates that a person should have to walk no more than 75 feet to reach a fire extinguisher.
ANSWER : A fire extinguisher, rated not less than 2A, shall be provided for each 3,000 square feet of the protected building area, or major fraction thereof. Travel distance from any point of the protected area to the nearest fire extinguisher shall not exceed 100 feet.
ANSWER : Every home needs at least one fire extinguisher, and most should have at least two or three. The number of fire extinguishers that you should have in your home depends on a couple of things: the size of your home and if your home is a multi-level home or not.
ANSWER : There are four classes of fire extinguishers – A, B, C and D – and each class can put out a different type of fire. Multipurpose extinguishers can be used on different types of fires and will be labeled with more than one class, like A-B, B-C or A-B-C.
ANSWER : To avoid putting workers in danger, fire extinguishers should be located throughout the workplace and readily accessible in the event of a fire. [29 CFR 1910.157(c)] You can usually find them in hallways, laundry rooms, meeting rooms, kitchens, mechanical/electrical rooms, and near exit doors.
ANSWER : The monthly checks should be documented. Also, the fire extinguisher should be inspected and certified annually by a fire protection equipment company. A complete breakdown and internal inspection must be done every 6 years. Both the annual and 6 year inspections shall be done by a fire protection equipment company.
Every 6 years, stored pressure fire extinguishers that require a 12-year hydrostatic test (e.g. dry chemical extinguishers) must be emptied and proper maintenance procedures performed [see NFPA 10(98), Sec. 4-4.3]. Again, this maintenance must be performed by an approved extinguisher servicing company.
  1. PULL... Pull the pin. This will also break the tamper seal.
  2. AIM... Aim low, pointing the extinguisher nozzle (or its horn or hose) at the base of the fire.
  3. SQUEEZE... Squeeze the handle to release the extinguishing agent.
  4. SWEEP... Sweep from side to side at the base of the fire until it appears to be
ANSWER : With an understanding of how to read a fire extinguisher label, now you must determine what size is best for your business. Here are the factors to consider:
  • The size of the room: Walls and doors are natural deterrents that help slow the spread of fire, so heed the Class B size rating when choosing an extinguisher for an individual room in your building. A standard 2A:10B:C extinguisher should be sufficient for an average-sized room with no significant hazards. However, a larger warehouse space may need a 4A:60B:C or 10A:80B:C extinguisher to cover the larger area.
  • The speed at which a fire could spread: Even the smallest fire extinguishers are effective if you employ them quickly after a fire ignites. However, some rooms encourage the flames to spread faster than others, such as a manufacturing facility with sawdust and other flammable debris on the floor. In short, if a fire is likely to spread quickly, you need a larger fire extinguisher.
  • The physical capabilities of your employees: Extinguishers with greater firefighting capabilities contain more extinguishing agent, making them larger and heavier. This is why you can’t simply purchase the largest possible extinguishers for every room in your business. For your consideration, a 2A:10B:C canister weighs 5 lbs; a 4A:60B:C canister weighs 10 lbs; and a 10A:80B:C canister weighs 20 lbs.

FAQ's about Fire Sprinkler Systems

ANSWER : Fire Sprinkler Systems are designed to keep a fire contained to an area until the fire department arrives. Many times, sprinkler systems can extinguish the fire.
ANSWER : Fire Sprinkler Systems are required to be inspected and tested annually.
ANSWER : Fire Sprinkler Systems deliver pressurized water to sprinkler heads. Once a sprinkler reaches the rated temperature, it activates spraying water.
ANSWER : Dry Sprinkler Systems are used in areas that are unheated and can freeze. Water is supplied to the dry valve. An air compressor keeps the entire system after the dry valve filled with air. When a sprinkler activates as normal, the air leaks out of the system at a rapid rate where the air compressor cannot keep up with. Once the water pressure overcomes the air pressure, the valve opens and floods the system with water.
  1. Draining down the system with a mesh bag over the main drain to collect any debris that may be present in the system for analyzing, opening multiple system locations and internally inspecting with a camera scope to investigate for any signs of M.I.C. (bacteria), excessive scaling (rust), or any obstructions that may clog a sprinkler in the event of a sprinkler activation during a fire.
  2. Removing all check valves including the FDC (fire department connection) check valve and internally inspecting them to make sure all parts are moving freely and operating normally.
  3. Internally inspecting the FDC line for any signs of debris. If any debris or scaling is present, a backflush of this line is performed to clear it.
  4. Replace any expired pressure gages.
ANSWER : The inspectors will open the ITV (inspector’s test valve) simulating a sprinkler activation. The air pressure will drop rapidly, and the compressor will not keep up. Once the water pressure overcomes the air pressure, the valve opens and floods the system. All the readings of air pressure, water pressure, valve trip time, water delivery time, etc. are noted on the report and compared to the initial acceptance test readings. If the readings are not comparable, there may be a problem with the system and an investigation will be needed.
ANSWER : Wet Fire Sprinkler Systems have a flow switch and Dry Sprinkler Systems have a water pressure switch. These switches are monitored by a Fire Alarm Control Panel. When the FACP receives an “Alarm” signal, that signal is transmitted to a Central Station Monitoring company that dispatches the Fire Department.