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TEST DEVICE FOR SEALS AND GASKETS AND A METHOD FOR INDEPENDENT CONTROL OF PRESSURE AND FLANGE OPENING

IP.com Disclosure Number: IPCOM000235997D
Publication Date: 2014-Apr-01
Document File: 3 page(s) / 51K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention proposes a device for evaluating seals and gaskets and a technique for independent control of pressure and flange opening. The device is a test rig that includes a top chamber, plates, two closed chambers, auxiliary seal, tested seal and proximity sensors. A chamber which is separated from testing chambers on top of the middle plate is pressurized to reduce gap on the tested seal. A chamber separated from testing chambers on the bottom of the middle plate is pressurized to increase gap on the tested seal.

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TEST DEVICE FOR SEALS AND GASKETS AND A METHOD FOR INDEPENDENT CONTROL OF PRESSURE AND FLANGE OPENING

BACKGROUND

The present invention relates generally to seals and gaskets and more particularly to a device for evaluating seals and gaskets.

Seal tests are generally performed in a pressurized testing chamber. The tests are performed by measuring leak rate by changing internal pressure or by measuring leaked gas volume or amount of leaking of a trace gas.

The gap between flanges to be sealed is an important parameter for seal evaluation. The gap is usually controlled by using a hydraulic press. Figure 1 depicts hydraulic press arrangement used for controlling gap between flanges to be sealed.

Figure 1

However, tests on seals used on centrifugal compressors are generally performed on downscaled samples, specifically, for high pressure applications. This is due to prohibitive dimensions of hydraulic press. Further, results of tests performed on downscaled seals are not always reliable for real size seals.

A conventional technique includes an inspection apparatus for in-situ leak testing of bell seal of a steam turbine. The apparatus includes a pair of inflatable bladders for defining a sealed volume having the bell seal as its only leakage path. Mass flow rate of pressurized air at various pressures through the bell seal is compared to the known flow rates through a similarly designed bell seal having various degrees of degradation. However, the above mentioned

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conventional technique is specific for seals used in steam turbines. Also, the technique is specific for in-situ leak measurements of seal and does not include method for gap variation in seals.

Another conventional technique includes a mechanical seal assembly. The seal assembly includes a leak detector mounted thereon for detecting low rates of liquid leakage across seal rings of the mechanical seal. However, the above mentioned conventional technique does not include seal test rig for seal evaluation.

One other conventional technique includes an apparatus for performing a mechanical seal test. The apparatus includes a housing, an adapting means having a central aperture for accommodating a test sample and replaceable to allow seals of different sizes to be tested, a pressing plate movable towards and away from the top wall and a plurality of clamp members for clamping test sample against top wall when the pressing plate is moved towards the top wall t...