SU1635027A1 - Method of determining the distance to leaks in elongated pipes - Google Patents

Abstract

The invention relates to pneumatic methods for determining the distance to leakage in long products, based on measuring the flow rate of gas supplied to the test product from two sides. The aim of the invention is to expand technological capabilities by determining the distance to a leak both at very small and large flows, and also to eliminate unproductive gas losses at large flows Gas flows into the controlled product 4 from two sides through differential valves 1, which their outputs through the measuring adjustable pneumatic resistances 2 are connected to the atmosphere, divided into unequal parts (supplied to product 4 and vented to the atmosphere) by establishing certain General for measuring the relationship between pneumatic resistances 2 and 3 differential valves. Then, adjusting the measuring pneumatic impedances 4 so that the readings of the differential pressure gauges 5 connected in parallel with the outputs 9 and 10 of the differential lines are zero, measure the parameters of the gas flows to the atmosphere, and calculate the distance to the leakage point lts, 1 il. with S (L

Description

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The invention relates to pneumatic methods for determining the distance to leaks in long products (cables, pipelines, etc.), based on measuring the flow rate of gas supplied to the controlled product from two sides.

The purpose of the invention is the expansion of technological capabilities by determining the distance to a leak, both at very large and at small leaks, as well as eliminating unproductive losses of the used gas at high times.

The drawing shows a schematic of the device with which the method for determining the distance to the leak is carried out.

The device contains a differential gas valve 1 (pneumatic distributor), tuning pneumatic resistance 2, stationary pneumatic resistance 3, measuring pneumatic resistance 4, differential pressure gauge 5, controlled product 6, flow meter 7, shut-off valve 8, supply pipe 9, outlet piping 10, the ends 11 and 12 of the unsealed product.

The method for determining the distance to the leak is as follows.

Differential gas valves are connected to the controlled product 6 at both ends 11 and 12, test gas is supplied through the supply pipes 9 and the stop valves 8 are closed.

After setting the flow and determining the approximate values of the gas flow rates by adjusting the tuning resistances for each differential valve, a convenient measurement ratio between the pneumatic resistances R2 and R- is set, i.e. there are equality:

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1- R6

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After performing this operation, the shut-off valves 8 are opened and by adjusting the measuring pneumatic resistances 4 usQ 5

0

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Zero readings on differential pressure gauges 5.

The absence of a pressure difference at the outlets of the inlet and outlet pipelines indicates that in each differential valve the inlet and outlet gas flows are distributed inversely proportional to the ratio of the resistances R ,,, RJ, tse "

t

QAZ

Qf nBQ |. (2)

The fixer reads on the scales of measuring pneumatic resistances 4 or the magnitude of gas flows measured by flow meters 7, the distance to the place of leakage of a long product is determined by the formulas:

a) based on resistance readings

1 JBsEl- 1. (-

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SC tdpA + tbp6

b) in terms of gas flows

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I QuUJ .. / ACh

x Olp: + J

6 B

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35

four

45 50

55

where 1 u. - distance to leakage from the point of delivery at the end 11 of the product; 1 - the length of the controlled product; adjustable readings

pneumatic resistances at supply points at the ends 11 and 12 of the product; QA, OV - the magnitude of the gas flow, measured at the ends 11 and 12 of the product;

Claims (2)

1. A method for determining the distance to a leak in long products, namely, that the p controlled product creates an overpressure of gas by supplying it from both sides of the product through differential valves, divide the gas flow to the supply to the product and vented to the atmosphere, regulate flows by changing the measuring pneumatic resistances at the outlet of the discharge piping to values at the pressure drops of each pair of inlet and outlet pipelines are equal to zero, the parameters of the outgoing flows are measured and, by their values, determine the distance to the leakage site, characterized in that, in order to expand the technological capabilities, for very small and large leaks, before dividing the flows, the values of the flows supplied to the product are estimated and set 6350276 pneumatic resistance of the differential valves so that the parameters of the diverted flows are within the selected measurement range, and when determining the distance to the leak, take into account the ratios of these pneumatic resistances. 2. Method pop. 1, which differs from 10 to the fact that, in order to eliminate unproductive losses of the gas used at large degrees of leakage, the discharge pipelines are locked during the adjustment,