A kind of assembly type single end face mechanical seal air tightness leakage detection device

Abstract

The utility model discloses a kind of single-end-face mechanical seal air-tightness leakage detection devices of assembly type, the lower end cap is fixed on the lower port of cylinder body, the center of lower end cap in cylinder body is fixed with vertical shaft, threaded shaft is set on the upper end of vertical shaft that projects outside cylinder body, detachable sealing upper end cap is fixed on the upper port of cylinder body, matching hole is set in the center of sealing upper end cap, movable sealing tray controlled by supporting spring is installed on vertical shaft in cylinder body, the diameter of movable sealing tray is smaller than the aperture of the matching hole of sealing upper end cap, replaceable supporting sealing ring is installed on the upper surface of sealing upper end cap, supporting sealing ring inner hole is matched with the gap of the shaft sleeve of the mechanical sealing assembly to be measured.The utility model has the advantages of reasonable structure, simple structure, strong versatility, convenient to carry, can realize the single-end-face mechanical seal air-tightness detection device of assembly type of real pressure static leakage test, solve the problems of unreliable test, environmental pollution, tooling redundancy and poor on-site applicability in prior art.

Description

Technical Field

[0001] This utility model relates to mechanical seal air tightness testing devices, and in particular to a containerized single-end mechanical seal air tightness leakage testing device. Background Technology

[0002] In industries such as petrochemicals, power generation, and pharmaceuticals, mechanical seals are key components for preventing media leakage in rotating equipment (such as centrifugal pumps and compressors). Among them, cartridge mechanical seals are widely used due to their advantages such as pre-assembly, convenient installation, and good alignment.

[0003] Based on their structural form, cartridge mechanical seals can be divided into two categories: double-end face and single-end face. The double-end face cartridge mechanical seal has two sealing end faces and an intermediate isolation chamber. Pressurized gas or liquid can be introduced into the isolation chamber to directly conduct a pressurized static leakage test. The test results are reliable and meet the requirements of actual working conditions. Single-end face cartridge mechanical seals have only one sealing pair and no independent isolation chamber. Traditionally, it is impossible to construct a closed pressurized space, making it difficult to conduct static tests under pressure.

[0004] Currently, the following methods are mainly used for leak detection of single-end face cartridge mechanical seals: Kerosene leakage method: Apply kerosene to one side of the sealed end face and observe whether oil stains appear on the other side. This method is a static test without pressure and has the following problems: It cannot simulate actual working conditions that exceed the operating pressure. Low detection sensitivity, making it difficult to detect even minute leaks; Kerosene is volatile and pollutes the environment, and requires special cleaning after testing, making the process cumbersome. It is not suitable for scenarios where customers reassemble using old parts on-site, as it lacks immediate and reliable verification methods.

[0005] Specialized leak testing fixture method: A customized test device, including a sealing cavity and a dummy shaft, is designed for each specification of single-end face seal to simulate its installation state on a pump. However, due to the wide variety of specifications of cartridge mechanical seals (significant differences in shaft diameter, length, spring type, transmission method, etc.), if a separate fixture is manufactured for each model, it will result in: a large number of fixtures, making management difficult; high material and processing costs; heavy warehousing and maintenance burden; and difficulty in covering non-standard or older models.

[0006] Electronic leak detection equipment: Although it can achieve automated detection, in practical applications, especially for embedded dynamic and static ring structures (such as silicon carbide embedded hard alloy), false alarms or missed alarms often occur due to differences in the thermal expansion coefficients of materials and uneven distribution of micro gaps, resulting in insufficient reliability.

[0007] In summary, existing technologies cannot meet the comprehensive requirements of versatility, environmental friendliness, portability, and the authenticity of pressure testing, and a new type of testing device is urgently needed. Utility Model Content

[0008] The purpose of this utility model is to provide a containerized single-end mechanical seal air tightness leakage detection device. It has a reasonable and simple structure, strong versatility, and is easy to carry. It can realize real pressurized static leakage testing and solve the problems of unreliable testing, environmental pollution, redundant tooling, and poor field applicability in the prior art.

[0009] The purpose of this utility model is achieved as follows: A containerized single-end mechanical seal airtightness leakage detection device, wherein a lower end cover is fixedly connected to the lower port of the cylinder, a vertical shaft is fixedly installed at the center of the lower end cover located inside the cylinder, a threaded shaft is provided at the upper end of the vertical shaft extending out of the cylinder, a detachable sealing upper end cover is fixedly installed at the upper port of the cylinder, a mating hole is provided at the center of the sealing upper end cover, a movable sealing tray controlled by a support spring is fitted on the vertical shaft located inside the cylinder, the diameter of the movable sealing tray is smaller than the diameter of the mating hole of the sealing upper end cover, a replaceable support sealing ring is installed on the upper sealing upper end cover, the inner hole of the support sealing ring is clearance fitted with the bushing of the mechanical seal assembly to be tested, sealing gaskets are respectively provided on the upper surface of the movable sealing tray and the upper ring surface of the replaceable support sealing ring, a vent hole for installing a pressure gauge is provided on one side of the cylinder wall, and an air inlet hole is provided on the other side of the cylinder wall.

[0010] The main body of this invention is a hollow cylindrical structure, preferably cylindrical, made of aluminum alloy or stainless steel, which is lightweight and pressure-resistant. One end is an open end for installing the mechanical seal under test; the other end is a closed end cap or a removable sealing end cap to ensure airtightness. A replaceable mechanical seal support ring is installed inside the main body near the open end; it has a central through hole with a diameter matching the outer diameter of the bushing of the seal under test; the support ring is fixed by a slot, screw, or quick-change mechanism for easy and rapid replacement; one set of devices is equipped with several support rings (e.g., 5-8 types), covering shaft diameters from 20mm to 80mm, meeting the testing needs of over 90% of commonly used single-end face cartridge seals.

[0011] Air inlet: Located on the side wall or end cover of the housing, it connects to an external clean compressed air or nitrogen source; equipped with a shut-off valve to control the gas flow.

[0012] Pressure monitoring device: including pressure gauge (e.g., 0–1.6 MPa, accuracy class 1.5) or digital pressure sensor; displays the pressure inside the cavity in real time. If there is a leak in the seal, the pressure will drop over time, intuitively reflecting the sealing performance.

[0013] Sealing end cap and auxiliary sealing structure: O-rings, fluororubber gaskets and other elastic sealing elements are provided between the end cap and the housing to ensure that there are no other leakage paths except for the mechanical seal itself during the test.

[0014] Pressure relief / venting valve (optional): Safely releases internal pressure after testing, improving operational safety.

[0015] Instructions for use: Select the corresponding support ring according to the shaft diameter of the single-end mechanical seal to be tested and install it inside the main housing; Install the entire mechanical seal (including the bushing, stationary ring assembly, rotating ring assembly, spring seat, etc.) from the open end, ensuring the stationary ring end face is tightly against the support ring; install and lock the sealing end cap to form a closed test chamber; introduce dry, clean gas through the inlet and pressurize it to a pressure higher than the actual working pressure of the seal (usually 1.1–1.5 times); maintain the pressure for 5–15 minutes and observe the pressure gauge reading; if the pressure is stable, the seal is qualified; if the pressure continues to drop, there is a leak, requiring repair or replacement; after the test, open the pressure relief valve to release the pressure, disassemble the seal, and the test is complete.

[0016] III. Beneficial Effects: Realistic live-line testing: Simulates actual operating conditions, resulting in more accurate and reliable test results; High versatility: By changing the support ring, it can be adapted to various shaft diameters, covering mainstream specifications and reducing the types of tooling; Environmentally friendly and pollution-free: It uses a gaseous medium and contains no harmful substances such as kerosene, meeting the requirements of green manufacturing; Simple to operate and intuitive results: No complex electronic systems are required, false alarms are avoided, and it is suitable for rapid on-site judgment; Portable and efficient: The machine is lightweight and compact, making it suitable for various scenarios such as workshops, warehouses, and construction sites; Low cost: One main body plus a few support rings can replace dozens of sets of special tooling, significantly reducing manufacturing and maintenance costs; Especially suitable for reuse and assembly scenarios: After customers reassemble and seal the equipment on-site using old parts, they can immediately verify its sealing performance and ensure the safe commissioning of the equipment.

[0017] The main shell has a uniform inner diameter of Φ90mm and a length of 150mm. It is equipped with 6 types of support rings, corresponding to the shaft diameter ranges: 20–25mm, 25–35mm, 35–45mm, 45–55mm, 55–65mm, and 65–80mm. The support ring is made of 45# steel or stainless steel with a finely machined surface to ensure a good fit with the end face of the sealing stationary ring. The air inlet uses a G1 / 4” quick-connect fitting, compatible with standard air supply lines; The pressure gauge is a shockproof type with a range of 0–1.6 MPa; The test pressure is set to 0.8 MPa (suitable for most chemical pump seals). The machine weighs less than 5kg and is equipped with a handle for easy carrying.

[0018] Practical verification has shown that this device can successfully test single-end face cartridge mechanical seals with various structures, including spring type, bellows type, balanced / unbalanced type, etc. It has good test repeatability and sensitivity on the order of 1×10⁻³ Pa·m³ / s. Attached Figure Description

[0019] The present invention will now be further described with reference to the accompanying drawings. Figure 1 This is a cross-sectional structural diagram of the present invention. Figure 2 This is a schematic diagram of the assembly structure for testing mechanical seals using this invention. Detailed Implementation

[0020] A containerized single-end mechanical seal airtightness leakage detection device, such as Figure 1 , Figure 2As shown, a lower end cover 2 is fixed to the lower port of the cylinder 1. A vertical shaft 3 is fixed to the center of the lower end cover 2 located inside the cylinder 1. A threaded shaft 4 is provided on the upper end of the vertical shaft 3 extending outside the cylinder 1. A detachable sealing upper end cover 5 is fixed to the upper port of the cylinder 1. A mating hole is provided in the center of the sealing upper end cover 5. A movable sealing tray 7 controlled by a support spring 6 is installed on the vertical shaft 3 located inside the cylinder 1. The diameter of the movable sealing tray 7 is smaller than the diameter of the mating hole of the sealing upper end cover 5. A replaceable support sealing ring 8 is installed on the upper sealing upper end cover 5. The inner hole of the support sealing ring 8 is clearance-fitted with the bushing of the mechanical seal assembly under test. Sealing gaskets 9 are respectively provided on the upper surface of the movable sealing tray 7 and the upper ring surface of the replaceable support sealing ring 8. A vent hole 10 with a pressure gauge is provided on one side of the cylinder wall of the cylinder 1. An air inlet hole 11 is provided on the other side of the cylinder wall of the cylinder 1. When testing the mechanical seal assembly, the assembly to be tested is inserted into the upper opening of the cylinder 1, ensuring that the end face of the stationary ring 13 of the mechanical seal assembly is tightly against the movable sealing tray 7. The lower surface of the pressure cap 14 of the mechanical seal assembly mates with the upper surface of the support sealing ring 8. The pressure plate 12 is locked onto the threaded shaft 4 extending from the mechanical seal assembly via a nut 15, forming the sealing test chamber. The replaceable support sealing ring 8 is fixed to the upper end cover 5 via a slot, screw, or quick-change mechanism. The replaceable support sealing ring 8 has six inner diameter options: 25mm, 35mm, 45mm, 55mm, 65mm, and 80mm, accommodating shaft diameters ranging from 20mm to 80mm for the mechanical seal assembly under test. The sealing groove of the through hole in the center of the movable sealing tray 7 is sealed to the vertical shaft 3 via an installed sealing ring. The cylinder 1 has an external dimension of 90mm in diameter and 150mm in length. The cylinder 1 is constructed of aluminum alloy or stainless steel.

Claims

1. A containerized single-end mechanical seal airtightness leakage detection device, characterized in that: in A lower end cover (2) is fixedly attached to the lower port of the cylinder (1). A vertical shaft (3) is fixedly mounted at the center of the lower end cover (2) inside the cylinder (1). A threaded shaft (4) is provided at the upper end of the vertical shaft (3) extending out of the cylinder (1). A detachable sealing upper end cover (5) is fixedly mounted on the upper port of the cylinder (1). A mating hole is provided at the center of the sealing upper end cover (5). A movable sealing tray (7) controlled by a support spring (6) is fitted on the vertical shaft (3) inside the cylinder (1). The diameter is smaller than the mating hole diameter of the sealing upper end cover (5). A replaceable support sealing ring (8) is installed on the upper end cover (5). The inner hole of the support sealing ring (8) is clearance-fitted with the bushing of the mechanical seal assembly to be tested. Sealing gaskets (9) are respectively provided on the upper surface of the movable sealing tray (7) and the upper ring surface of the replaceable support sealing ring (8). A vent hole (10) with a pressure gauge is provided on one side of the cylinder wall of the cylinder body (1), and an air inlet hole (11) is provided on the other side of the cylinder wall of the cylinder body (1).

2. The containerized single-end mechanical seal airtightness leakage detection device according to claim 1, characterized in that: When testing the mechanical seal assembly, the mechanical seal assembly to be tested is inserted into the upper opening of the cylinder (1), so that the end face of the stationary ring (13) of the mechanical seal assembly is tightly attached to the movable sealing tray (7), the lower plane of the pressure plate (14) of the mechanical seal assembly is matched with the upper plane of the support sealing ring (8), and the pressure plate (12) is locked on the threaded shaft (4) extending out of the mechanical seal assembly by the nut (15) to form a sealing test chamber.

3. The containerized single-end mechanical seal airtightness leakage detection device according to claim 1, characterized in that: The replaceable support seal ring (8) is fixed to the upper end cover (5) by a slot, screw or quick-change mechanism.

4. A containerized single-end mechanical seal airtightness leakage detection device according to claim 1 or 3, characterized in that: The replaceable support seal ring (8) has six inner hole diameters: 25mm, 35mm, 45mm, 55mm, 65mm, and 80mm, which can be adapted to the shaft diameter range of 20mm-80mm of the mechanical seal assembly to be tested.

5. The containerized single-end mechanical seal airtightness leakage detection device according to claim 1, characterized in that: The sealing groove of the through hole in the center of the movable sealing tray (7) is sealed with the vertical shaft (3) by the installed sealing ring.

6. The containerized single-end mechanical seal airtightness leakage detection device according to claim 1, characterized in that: The outer dimensions of the cylinder (1) are 90 mm in diameter and 150 mm in length.

7. The containerized single-end mechanical seal airtightness leakage detection device according to claim 1, characterized in that: The cylinder (1) is made of aluminum alloy or stainless steel.

Images