Backflow is a term in plumbing for an unwanted flow of water in the reverse direction. It can be a serious health risk for the contamination of potable...

A backflow prevention device is used to protect potable water supplies from contamination or pollution due to backflow. In water distribution systems,...

The term Eurasian backflow, or Eurasian back-migrations, has been used to describe several pre-Neolithic and Neolithic migration events of humans from...

A reduced pressure zone device (RPZD, RPZ, or RPZ valve) is a type of backflow prevention device used to protect water supplies from contamination. RPZDs...

toilets, while avoiding overflow and (in the event of low water pressure) backflow. The modern ballcock was invented by José Antonio de Alzate y Ramírez,...

the heart or between heart chambers. It is the circulatory equivalent of backflow in engineered systems. It is sometimes called reflux. The various types...

blood is maintained by one-way (unidirectional) venous valves to prevent backflow. In the lower limbs this is also aided by muscle pumps, also known as venous...

to allow blood flow and which then close together to seal and prevent backflow. The mitral valve has two cusps, whereas the others have three. There are...

atrium to the right ventricle during diastole, and to close to prevent backflow (regurgitation) from the right ventricle into the right atrium during right...

hose spigots, hose bibs, and wall hydrants to have a vacuum breaker or backflow preventer, so that water cannot return through the spigot from the hose...

Sometimes called a check valve or a backflow preventer, a chemigation valve is an apparatus designed to protect water supplies from agricultural chemicals...

Lean TAPS combustor reduces NOx gases with required pressure loss and backflow margin. Fan blades have steel alloy leading edges and the composite fan...

commonly used in medical applications to prevent contamination due to backflow. One end of the valve is stretched over the outlet of a supply line, conforming...

minimum is an air gap. See cross connection control & backflow prevention for an overview of backflow prevention methods and devices currently in use, both...

A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination. It is different...

may also occur with valvular insufficiency (regurgitation), which allows backflow of blood when the incompetent valve closes with only partial effectiveness...

a clapper valve (if not designed into the hydrant already) to prevent backflow into the hydrant. Additionally, residents who wish to use the hydrant to...

fail; the second is that testicular valves that are supposed to prevent backflow fail (venous insufficiency) leading to swelling and compression of the...

regardless of flow direction or pressure. In addition to closing in response to backflow or insufficient forward pressure (normal check-valve behavior), it can...

blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also...

practice, is an arrangement of pipes formed into a vertical loop to prevent backflow of water within the plumbing potable water system. Since a siphon has a...

of the valve function thereby opening up the ureter to backflow. The main risk of such a backflow is the spreading of urinary tract infections up into the...

many causes. GERD is the most common cause of esophagitis because of the backflow of acid from the stomach, which can irritate the lining of the esophagus...

non-potable fluid, the water supply shall be protected against backflow by a backflow preventer. Where a hose bibb is installed outside a building, inside...

Anorectal varices are collateral submucosal blood vessels dilated by backflow in the veins of the rectum. Typically this occurs due to portal hypertension...

itself. Defects may be due to narrowing of one or more valves (stenosis), backflow of blood, through a leaky valve (regurgitation), or the presence of abnormal...

A backwater valve is a backflow prevention device used to prevent outbound water through a dwelling's drain pipes from re-entering -- "back flowing"—into...

v t e Plumbing Fundamental concepts Air gap (plumbing) Backflow Compatibility (chemical) Corrosion Drain (plumbing) Drinking water Fuel gas Friction loss...

form of backflow prevention. A common use of the term "air gap" in domestic plumbing refers to a specialized fixture that provides backflow prevention...

one-way valve at the vesicoureteral (ureteral-bladder) junction preventing backflow. The valve is formed by oblique tunneling of the distal ureter through...