Rubber Gasket Research Articles

SYNTHETIC FUEL CONSIDERATIONS FOR NAVAL SHIPBOARD USE

ABSTRACTSynthetic fuels are assessed with respect to their potential use aboard Navy ships. The status of petroleum resources and the development of fuels from shale, coal, and biomass is summarized. A scenario of the projected availability of these fuels is presented which shows the sensitivity to funding and schedule. Diesel engine and gas turbine combustor tests with small quantities of coal derived and shale derived fuels are described and these tests results are evaluated for shipboard applications. Special shipboard modifications are discussed such as the replacement of rubber base seals, gaskets, and hoses with viton and teflon, and the use of stainless steel piping because of the fuel characteristics. Considerations for dual fuel systems using Diesel Fuel Marine for starting, stopping, and maneuvering are included based upon early test results. Consideration is given to the use of these fuels in the shipboard environment since they require special handling and adoption of personnel safety measures.

Otitis Media and Fever-Reply

In Reply.— The statement by Drs Wright and Olson that most of our cases [of acute otitis media] were seen by numerous different pediatric residents, among whom there may not be uniform subjective criteria for making the is the crux of the problem. We agree that such a diagnosis may not be based on uniform subjective criteria. This very fact may be reflected in the ultimate outcome—a higher frequency of fever and otitis media in the Kansas City study. However, in our study, in a private practice setting, all the children were examined by the same pediatrician. Meticulous removal of all gross cerumen and the use of brilliant halogen illumination was the rule; an otoscope head with a rubber gasket on the lens cap ensured a perfect airtight seal. Table 3 of our article shows that of 290 patients who had acute otitis media, a myringotomy, and a culture,

An improved solar cooker

An improved hot box type solar cooker (SC-2) has been designed, developed and tested. It is an improvement on the solar cooker SC-1 earlier developed at the institute. The cooking chamber has properly been optimized for cooking the food for a family of five persons. A rubber gasket has been provided at the boundary of the openable door to prevent the leakage of hot air, thus increasing the pressure in the cooking chamber. Different cooking trials like boiling, roasting and baking were successfully conducted and the cooker was found useful from 8.00 a.m. to 5.00 p.m., even during a winter month. The efficiency of the cooker was found to be 41.2 per cent.

The Chamber/Dish: an improved vessel for cell and explant culture.

A vessel consisting of a Teflon well former, metal base plate, rubber gasket, and variable growth surface has been constructed. It is nontoxic, autoclavable, and reusable. It provides for ready access into the growth chamber, plus an optically clear lower surface for improved microscopic resolution. The vessel has been used successfully with several different eucaryotic and procaryotic cell systems. Morphology of cells and yields (as measured by total protein and ATP) are comparable to those noted with other vessels. This Chamber/Dish can accommodate almost any type of growth substrate in the form of films or sheets. It appears to have widespread application for the growth of cells and explants in vitro.

Ultrasonic system for the inspection of rubber gaskets

An ultrasonic test system for the inspection of rubber gaskets, used to join lengths of ductile iron pipe, is described. The system, developed by the Tubes Division of the British Steel Corporation, is capable of detecting manufacturing faults using a through transmission technique.

Ultrasonic system for the inspection of rubber gaskets

An ultrasonic test system for the inspection of rubber gaskets, used to join lengths of ductile iron pipe, is described. The system, developed by the Tubes Division of the British Steel Corporation, is capable of detecting manufacturing faults using a through transmission technique.

Overview of Buried Pipelines Under Seismic Loading

Damage and response behavior of buried lifelines, such as submerged tunnels and gas, water, and sewer distribution lines, subjected to earthquakes are reviewed. Current design practice, analysis procedures, code provisions, and the latest published research are considered. Damage surveys indicate that pipelines with flexible joints (rubber gasket), buried in uniform firm soil experience less damage during earthquakes. The seismic response behavior is governed by the displacements of the ground. Ductility to allow pipeline movement is the most important factor in designing such systems. Various passive design practices, such as carefully selecting site locations, ductile pipeline materials, and providing fail-safe systems are presently being used to mitigate the effects of earthquakes. There are no code provisions in the United States to design buried lifelines for seismic loads. Engineers and researchers are working toward developing seismic design codes for buried pipelines.

Leakage characteristics of flanged pipe joints

Standard flanges for five widely differing pressure ratings, having a wide range of different joint surface profiles, were sealed by flat rubber or asbestos gaskets. Different initial bolt tensions were applied and the variation of clamping force with internal pressure was measured up to leakage of the joint. The joint efficiency, defined as: (end thrust due to leakage pressure on bore area of pipe)/(total initial bolting force), is not affected by variations in joint-face surface finish if machining grooves across the joint surface are avoided. Minimum values of joint efficiency are given. The effects of gasket material, width and thickness and number of bolts on joint efficiency are considered.

Increasing the reliability of articulated support assembles for suction dredge scarifier frames

1. To improve the operation of the articulated support assembly of the scarifier, the clearance determined from Eq. (1) should be used at the trunnion—support assembly. 2. For the new suction dredges being designed, it is recommended to use the scarifier support assembly shown in Fig. 4, as well as absorbing elastic rubber gaskets. The trunnion diameter is determined from the scarifier capacity (Table 2), and the allowable misalignment, independently of the scarifier capacity, is 10–20 mm.

Crevice corrosion of carbamate pump cylinders

Intensive crevice cor ros ion occurs under rubber gaskets in the valve chambers of carbamate pump cylinders made of austenitic steels 10Kh17N13M3T, 08Khl7N15M3T, and Kh17N13M3B, which frequently causes failure of the seal . Examination of fourteen cylinders made Of austenitic steels af ter 2500-6100 h of operation showed cor ros ion in the intake valve chamber in a band 2 mm wide around the c i rcumference (the diameter of the gasket was 6 mm), the depth of the attack reaching 2 mm. The width of the corroded band in the valve chamber on the discharge side was ~3 mm, with a depth of 1 .5 mm.

アルミニウム陽極酸化皮膜の新しい耐アルカリ試験法について

In “Japanese Industrial Standard”, there is specified that the alkali resistance of anodic oxide film on aluminum shall be indicated by the time (sec.) required for dissolution of the film and exposure of the ground metal by action of the testing solution (10% NaOH); and is also specified that the alkali dropping method shall be applied for the test. In order to get more accurate and reproducible test results, an improved testing method, quite different from the dropping method, was studied by the author. In this improved method, a Monel metal cell fitted with a hard rubber gasket was in close contact with the surface of specimen; and then, the cell was filled with the testing solution. The exposure of ground metal was determined by measurement of a certain value of electromotive force with a self-balancing recorder between the cell and the ground metal. For simpler and more accurate operation, the author designed and practised a new apparatus, which automatically indicates the test results by digital data, according to the results of experiments. In general, in the tests of chemical reaction, the fluctuations of testing temperature must be controlled within a narrow range as possible. In this method, it was possible to maintain the temperature of specimen within the range of 55±0.2°C by touching the back of specimen with water regulated at the testing temperature (35°C). As the results of above improved testing method for various specimens which had been formed under different conditions, the variation of resistance was 5% maximum, showing more accurate and reproducible values.

Laboratory suggestion: a simple modification to extend gasket life and prevent leakage on shaft-driven centrifugal pumps.

A method of placing a small teflon sleeve over the shaft which cuts down friction between the metal shaft and rubber gasket and allows a tighter, more lasting seal is described. Special reference is made to the water pump assembly on the Model 113 and 123 IL Blood Gas Apparatus with the Model 127 constant temperature bath.

Sealing properties of joints with Paronit and rubber gaskets

Sealing properties of joints with Paronit and rubber gaskets

Metering High Viscosity Elastomers

This article describes processing equipment for elastoplastics. Equipment models described are in production on such applications as construction application for deck coatings and pavement joint sealing, elastomer moldmaking, encapsulation of electrical and electronic devices. Advances are being rapidly made in other industries, too. Automobile manufacturers, for example, are installing windshields and back lights with a polysulfide material, replacing the conventional rubber gasket. Aircraft manufacturers operate central “Sealant Cribs” to supply in-plant locations with elastomeric sealants for sealing of integral fuel tanks. With manufacturers guaranteeing product performance for 5 and 10 years, automatic metering and mixing equipment is becoming an integral part of the manufacturing process in many industries.

The use of thin rubber gaskets for the hermetic sealing of joints at low temperatures

The use of thin rubber gaskets for the hermetic sealing of joints at low temperatures

Report on a radium safe and lead testing system.

A radium safe has been constructed, using 46 standard 2 × 4 × 8-inch lead bricks stacked together. Troughs were dug in four of the bricks and fitted with plastic trays. These constitute the drawers which are surrounded with aluminum shells to prevent marring and are fitted with stops so that they cannot come completely out. The drawers are separated by 1/8-inch steel plate, and the entire safe is surrounded by the same material. The outside surface is an aluminum shell, and the door is 1/8-inch steel fitted with a rubber gasket so that the safe is almost air-proof. The base is 1/2-inch steel plate, and the safe sits on a dolly with four wheels mounted in high-strength bearings so that the 1,200 pound unit can be moved. A small hole was drilled in the top of the safe (through the aluminum and steel sections) for connection to a vacuum pump. Short lengths of plastic tubing are connected to both the safe and the pump. The two pieces of plastic tubing are in turn connected with aluminum tubing which is fitted into holes drilled through two rubber stoppers. These stoppers will fit into either end of a 3/4-inch diameter aluminum cylinder about three inches long. Activated charcoal is placed in the cylinder with a plug of cotton at each end. The purpose of this system is to provide routine leak-testing of a radium supply without undue exposure to the person doing the testing. A charcoal filter can easily be inserted in the vacuum line. Only a few seconds of pumping time are required to determine leakage, using an end-window G-M tube and Baird-Atomic Counter with a normal background of about 20 counts per minute. It is planned to modify the filter construction in the future for use with a well-type scintillation counter. Accumulated data which were taken with a 1.33 mg leaking radium needle, show relations between count-rate, pumping time, and leakage time. A net count rate of 22 counts per minute was obtained from a fifteen-second pumping when the needle had been in a sealed container seven days after being exhausted of its free radon. Obviously, if a leak is detected, the operator must receive some exposure in isolating the defective needle by using the old test tube (or equivalent) system.

Erratum for “Calculation of Diameter of Stretched Rubber Gasket”

Erratum for “Calculation of Diameter of Stretched Rubber Gasket”

Biologic Degradation of Rubber Gaskets Used for Sealing Pipe Joints

This article discusses the examination of a representative number of American gaskets with regard to their resistance to biologic attack, under exactly the same conditions under which the Dutch rings were tested, which was reported in a previous article on the degradation of natural rubber gaskets used for sealing joints of asbestos‐cement pipes in the Netherlands. Sixty‐eight gaskets were tested; with regard to the compounding, 19 gaskets were manufactured from natural rubber or synthetic polyisoprene, 46 from different kinds of synthetic rubber, and three were mixed compounds. The test was carried out with the same dune water used in the experiments with Dutch rings and was continued for two years. All samples were tested in duplicate.

Flat and Slope-Sided Rubber Gaskets

First Page

Rubber Gaskets for Pipe

This article discusses the development of several types of flexible joints for all sizes of concrete pressure and sewer pipe. The behavior of rubber gasket joints and the material properties required for successful performance are described. Except for the 44‐durometer gaskets tested for contact pressure and compression set of stretched specimens, all results and conclusions are based upon the rubber and steel joint in which the fully confined 60‐durometer gasket fills the gasket groove.