Manhole cover positive and negative pressure performance test bench and manhole cover positive and negative pressure performance test method

Abstract

The invention discloses a manhole cover positive and negative pressure performance test bench and a manhole cover positive and negative pressure performance test method. The test bench comprises a frame, the center of the frame is provided with a test chamber, and the upper part of the test chamber is provided with a manhole cover. A semi-circular symmetric pressing plate is arranged above the manhole cover. Two cylinders are symmetrically arranged on the two sides of the frame, and the piston rods of the cylinders are connected with the semi-circular symmetric pressing plate. The lower part of the test chamber is provided with an air inlet, an air intake port and a pressure sensor. The air inlet is connected with an air source through a two-position two-way electromagnetic directional valve I. The air intake port is connected with a vacuum pump through a two-position two-way electromagnetic directional valve II. Rodless cavities and rod-containing cavities of the cylinders are connected with the air source through a three-position four-way electromagnetic directional valve. The test method comprises four steps: manhole cover mounting and compressing, test chamber air inflation detecting, test chamber air intake detecting, and manhole cover unloading and disassembling. The test bench and the test method make up for the shortcomings of the existing manhole cover detection device and test method. Integration of the automatic compressing, testing and unloading and disassembling steps in the process of manhole cover positive and negative pressure performance test is realized.

Description

technical field [0001] The invention relates to a test bench and method for positive and negative pressure performance testing of a manhole cover. Background technique [0002] The manhole cover is widely used on the oil tank of the oil tanker. Its unique structural design can ensure that the pressure in the oil tank is in a reasonable range, and effectively prevent the oil tank from collapsing due to low internal pressure, or due to excessive pressure. There is a high incidence of safety accidents involving oil tank explosions. The main principle is to set a breathing valve on the manhole cover. When the vehicle accelerates, the internal fluid activity reduces the pressure in the tank, and the breathing valve can be opened to effectively balance the internal pressure, so that the pressure in the tank will not be too low; When the tank truck slows down or is exposed to the sun, the pressure in the tank rises sharply, and the breathing valve can be opened so that the pressur...

AI Technical Summary

Problems solved by technology

At the same time, because the breathing valve is installed on the manhole cover, even if the breathing valve is qualified, there may be errors in the manufacture of the cover and the installation process with the breathing valve body, which will affect the normal function of the manhole cover.

However, there is no device and test method for detecting manhole covers at present, especially the device for detecting the entire manhole cover as a whole is particularly lacking.

In addition, as a detection system, it must have high accuracy and reliability. The accuracy of the detection results directly determines the pass rate of the product and affects whether the product can be used well.

Images