Sized surge tank (open or bladder type) is objectively safer and more reliable than a surge anticipator valve, because it has no moving parts and absorbs the surge instantly and forever.
In practice, however, surge anticipator valves are installed 20× more often because they are cheaper, smaller, and work well enough (75–90% reduction) for most buildings.
The surge anticipator valve (also called surge anticipation valve or pressure-anticipator relief valve) is a special automatic valve installed on the discharge side of fire pumps, booster pumps, or any pump that can create dangerous water hammer when it starts or stops suddenly.
Its only job is to protect the piping system from extreme pressure spikes caused by hydraulic transients (water hammer)
ΔP = ρ × a × Δv Where:
Common Causes of Water Hammer
Water hammer (also known as fluid hammer, hydraulic shock, or surge) is a pressure surge or shock wave that occurs in a piping system when a fluid (usually liquid, most commonly water) in motion is suddenly forced to stop or change direction rapidly.
This sudden change creates a high-pressure wave that travels back and forth through the pipe at the speed of sound in the fluid, often producing loud banging noises (like a hammer hitting the pipe) and potentially causing serious damage.
A DEVIATION OF THE PIPEWALL FROM THE IDEAL CONTOUR OF MORE THAN 15% OF THE NOMINAL WALL THICKNESS PERPENDICULAR TO THE SURFACE.
RAPID REDUCTION OF METAL TEMPERATURE AFTER A HOT FORMING PROCESS BY USING WATER.
A PIPE CONNECTOR THAT IS MADE OF TWO MATING PIECES, ONE FOR EACH END OF THE TWO PIPES BEING JOINED. THE TWO HALVES OF THE UNION ARE HELD TOGETHER BY A THREADED RING.
A DEVICE WHICH PREVENTS TRANSLATIONAL MOVEMENT IN ONE DIRECTION ALONG EACH OF TWO AXES. A “TWO-AXIS DOUBLE-ACTING STOP” PREVENTS TRANSLATIONAL MOVEMENT IN THE PLANE OF THE AXES WHILE ALLOWING SUCH MOVEMENT NORMAL TO THE PLANE.
MEASURE OF RESISTANCE TO DEFORMATION, STRENGTH IS INVERSELY PROPORTIONAL TO TOUGHNESS
POST WELD HEAT TREATMENT USED TO RELIVE THE TRAPPED ELASTIC STRESS
A GASKET TYPE FORMED BY ALTERNATELY WINDING STRIPS OF METAL AND SOFT FILLER MATERIAL AROUND A MANDREL
A PIPE ATTACHMENT DETAIL IN WHICH A PIPE IS INSERTED INTO A RECESSED AREA OF A FITTING, AND THEN FILLET WELDED BETWEEN ITS OUTSIDE DIAMETER AND THE FITTING END.
A DEVICE USED TO SUSTAIN A PORTION OF PIPING SYSTEM WEIGHT PLUS ANY SUPERIMPOSED VERTICAL LOADINGS
A DEVICE WHICH PERMITS ROTATION BUT PREVENTS TRANSLATIONAL MOVEMENT IN AT LEAST ONE DIRECTION ALONG ANY DESIRED AXIS. IF TRANSLATION IS PREVENTED IN BOTH DIRECTIONS ALONG THE SAME AXIS, THE TERM “DOUBLING-ACTING STOP” IS PREFERABLY APPLIED. IN COMMON USAGE, A STOP NORMALLY ACTS ALONG THE DIRECTION OF THE PIPE AXIS.
A NONMETALLIC BLANKET THAT FORMS ON THE TOP OF THE MOLTEN WELD METAL. IT HELPS TO CONTROL THE TEMPERATURE, THE COOLING RATE, AND ASSISTS IN PREVENTING AND REMOVING IMPURITIES FROM THE WELD METAL.