FIELD: heating.
SUBSTANCE: apparatus is intended for flow-line individual and pairwise grading (verification) of pairs of volume flow meters used in heat meters for closed and open water heat supply systems. The apparatus is comprised of supply and return pipelines and three reference volume flow meter units. The first reference unit is connected to the beginning (inlet) of the supply pipeline and measures the set flow value. The second (bypass) reference unit overlaps the measuring section of the return pipeline containing the verified (calibrated) volume flow meters and a controlled adjusting valve. The unit is connected to the return pipeline by two shut-off valves. The third reference unit similar to the second unit is connected to the supply pipeline. Part of the flow (accurately measured by the comprised reference flow meters) can be passed through the bypass units bypassing the graded (calibrated) flow meters located on one of the pipelines (supply or return) creating a set and accurately measured value of flow difference. The set value of volume water flow difference, positive or negative, is set by a part of the water bypassing the graded flow meters being passed by a controlled adjusting valve on the return (supply) pipeline through the corresponding reference bypass unit where the flow value is corrected by the controlled adjusting valves according to the readings of the reference flow meters of this unit to be as close as possible to the value of said flow difference. The operation of determining the value of flow difference by the measured value difference by the graded flow meters exhibiting an unacceptably large flow difference measurement error component is not executed therein.
EFFECT: increased productivity and accuracy of grading of pairs of identical volume flow meters of any type within heat meters in reproducing volume flow differences in direct and return pipelines of water heat supply systems (WHST).
5 cl, 5 dwg
