RU2822589C2 - Method of connecting device for checking adjustment and adjustment of safety valves - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention relates to the technology of checking the setting and adjustment of safety valves at gas distribution stations (GDS). Method of connecting a device for checking the setting and adjustment of safety valves consists in the fact that gas for checking the setting of the safety valve is supplied with the required increased outlet pressure from the inlet high-pressure pipeline of the GDS to the inlet of the safety valve of the safety valve unit through the device for checking the setting and adjustment of the safety valves. Device for checking the setting and adjustment of safety valves, consisting of a high-pressure reducer with pressure gauges, connected to the housing, on which a pressure gauge with a control pointer is installed, is connected to the inlet pipeline of the GDS by means of an inlet portable pipeline through a gas bleed valve, and due to the outlet portable pipeline it is connected by means of a ball valve to the input of the safety valve through a spacer, which is an annular chamber with inlet and outlet flanges, with welded side union, installed between inlet flange of safety valve and outlet branch pipe of switching device.

EFFECT: invention is aimed at increasing accuracy and reducing labour intensity of works on checking and adjusting safety valves.

1 cl, 3 dwg

Description

The invention relates to a technology for checking the settings and adjustments of special full-lift safety valves of the SPPK type, spring full-lift safety valves of the PPK type and other safety valves (hereinafter referred to as safety valves) as part of a block of safety valves of gas switching units during the operation of gas distribution stations (hereinafter referred to as GDS).

There is a known method for checking and adjusting safety valves by changing the initial operating mode of the gas distribution station with closing the inlet and outlet valves and transferring the gas distribution system to work along a bypass line (STO Gazprom 2-2.3-1122-2017 Gas distribution stations. Operating rules: approved and put into effect by decree PJSC "Gazprom" dated 07/03/2017 No. 202: date of introduction 09/15/2017 - clause 7.4.3). This method consists of supplying gas directly from the high-pressure inlet pipeline (hereinafter referred to as the inlet pipeline) into the low-pressure outlet pipeline (hereinafter referred to as the outlet pipeline) through the GDS bypass line by regulating the initial operating pressure using a bypass line valve, followed by an increase to the required increased output pressure, setting and testing the safety valve, at which it should open and then release the gas into the atmosphere to prevent a further increase in pressure in the outlet pipeline of the gas distribution system and protect gas distribution networks from emergency situations. After completing the procedure for checking and adjusting the safety valve, the inlet and outlet valves of the gas distribution system are opened, and the bypass line valves are closed to return the operating mode of the gas distribution system to its original mode.

The disadvantage of this method is that work on the bypass line is “special operating conditions for the gas distribution station”, and it is necessary to inform the dispatcher and the consumer in advance (within the established time frame) that gas reduction will be carried out manually. While working along the bypass line, the operator must continuously monitor the inlet pressure and gas pressure at the outlet of the gas distribution system, recording these parameters every 30 minutes, and also monitor the operation of the odorization unit. Thus, the procedure for checking and adjusting safety valves is a very labor-intensive operation and is accompanied by a high risk of disruption of gas supply to the consumer.

A device for regulating and monitoring pressure settings of safety valves is known (RU 2578489 C1). The device contains a force sensor connected to the controller. A support washer is additionally installed in the safety valve, consisting of a cover, inlet and outlet flange connections, seat, spool, lower and upper support washers, rod, spring and adjusting sleeve. The force sensor is installed between the upper valve support washer and an additionally installed washer. The essence of the device is to measure the elastic force of the safety valve spring using a force sensor connected to the controller and calculate the setting pressure from the measured value of this force, the weight of two support washers, a force sensor, a spring and a rod with a spool.

The disadvantage of this method is not the direct measurement of the response pressure, but indirect calculations. This method does not provide reliable testing and configuration results.

The closest method is the method of checking and adjusting safety valves using a special device (RU 2592530 C2). This method consists in the fact that the gas for setting and testing the safety valve is supplied with the required increased output pressure from the high-pressure inlet pipeline of the gas distribution system to the safety valve block at the inlet of the adjustable safety valve through a special device. This device consists of a portable removable pipeline with a reducer, a tee and a pressure gauge. The device is connected to the high-pressure inlet pipeline of the gas distribution system and to the adjustable safety valve through pipes (fittings) using adapters, before checking and adjusting the safety valves. Installation of branch pipes (fittings) is carried out during the period of planned shutdown of the gas distribution system by welding.

The safety valve of the safety valve block that has been taken out of operation is tested. Adjustment of the pressure supplied to the input of the tested (adjustable) safety valve is carried out using a reducer included in the device; control of the response pressure of the safety valve is carried out using a pressure gauge included in the device.

In the case of using a prototype, the need to transfer the gas supply to the bypass line and change the initial mode of the gas distribution system is eliminated.

The disadvantages of the prototype are:

1. The need to shut down the gas distribution system and carry out hot work for the purpose of the initial installation of pipes (fittings) for connecting the device.

2. Low accuracy in determining the opening pressure of the safety valve due to the fact that at the moment the valve is activated, the pressure drops sharply, the pressure gauge reading changes quickly, and it is difficult to track the exact operation pressure. To obtain a reliable result, the operation must be repeated many times.

The objective of the invention is to eliminate the need to stop the gas distribution system and carry out hot work on the installation of pipes (fittings) for connecting the device and to increase the accuracy of determining the opening pressure of the safety valve, ensuring that the result is recorded on the device itself, eliminating operator error (“human factor”).

The technical result is a reduction in financial losses associated with shutting down the gas distribution system and carrying out hot work during the installation of branch pipes (fittings) for connecting the device, as well as increasing the accuracy and reducing the labor intensity of the work on checking and adjusting safety valves.

The technical result is achieved by creating the device described below for checking and adjusting safety valves and improving the method of connecting it in comparison with the prototype.

The essence of the invention is illustrated in Fig. 1. The device consists of a high-pressure reducer 3 with pressure gauges 4 and 5. Reducer 3 is connected to a housing (tee) 1, on which a pressure gauge 2 with a control arrow is installed (without reverse). The device has inlet 6 and outlet 7 portable pipelines.

The connection of the device for checking and adjusting the safety valve is carried out in accordance with the diagram shown in Fig. 2. Device 8 at the inlet portable pipeline is connected to the gas sampling valve 13 on the pressure gauge installed on the inlet pipeline of the GDS. To connect the output pipeline of the device, a special spacer 14 with a ball valve 15 is mounted between the inlet flange of the safety valve 10 and the outlet pipe 11 of the switching device 12. The design of the spacer is shown in Fig. 3. It is an annular chamber with inlet and outlet flanges, with a welded side fitting. The spacer is mounted on the safety valve put into reserve immediately before testing and adjustment work is carried out. Thus, when connecting the device, stopping the GDS is not required. After the work, the spacer can be dismantled, but can be left as part of the safety valve block.

Checking the settings and adjusting the safety valve is carried out in the following sequence. Previously, the gearbox 3 (Fig. 1) of the device is installed in the fully closed position. Taps 13 and 15 open (Fig. 2). The inlet pressure is monitored using the inlet pressure gauge 4 of the device. Next, reducer 3 smoothly increases the output pressure until the safety valve is activated. The output pressure is controlled by pressure gauge 5 (Fig. 1). After the safety valve is triggered (opened), it is necessary to close the gas sampling valve 13, after which the pressure in the safety valve begins to decrease and the valve closes. The actual pressure at the beginning of the valve opening remains fixed on pressure gauge 2, and the actual pressure at the moment the valve closes is displayed on pressure gauge 5.

Claims (1)

A method for connecting a device for checking the settings and adjustments of safety valves, which consists in the fact that gas for checking the settings of the safety valve is supplied with the required increased output pressure from the high-pressure input pipeline of the gas distribution station (GDS) to the input of the safety valve of the safety valve block through the device for checking the settings and adjustment of safety valves, characterized in that a device for checking the settings and adjustment of safety valves, consisting of a high-pressure reducer with pressure gauges connected to a housing on which a pressure gauge with a control arrow is installed, is connected to the inlet pipeline of the gas distribution system using an inlet portable pipeline through a tap for gas sampling, and due to the portable outlet pipeline, it is connected using a ball valve to the inlet of the safety valve through a spacer, which is an annular chamber with inlet and outlet flanges, with a welded side fitting, installed between the inlet flange of the safety valve and the outlet pipe of the switching device.