Explosive decompression resistance

From the above table it is seen that the coated filler accommodates more carbon dioxide leading to blistering in the seal, which is known as explosive decompression. It becomes evident that rubber compounds that have low permeation rates are chemically resisting the permeation of gases and are the best to minimize blistering due to the cavity or vacuoles in the rubber or polymer matrix. 

Table 5.2 [5] shows the effects of four important filler variables on the physical properties of a sealing compound, those being quantity, surface area, structure and surface reactivity. The resistance to blistering, or explosive decompression, is found to increase with an increase of all the four variables. Table 5.2 shows how these properties change as each of these variables increases. It should be studied in conjunction with Figure 5.1, from which the specific properties can be optimized. Since each of these variables can affect properties differently, and cross-link density of the compound will have yet another effect, (shown Figure 5.1), the choice of properties to be optimized should be selected very carefully, and should be limited. 

Explosive decompression High-pressure extrusion Effect of corrosion inhibitors Effect of hydrogen sulphide Steam/add resistance Methanol resistance... 

Correct choice of elastomer as the base for the seal compound is most important, as is the correct choice of compounding ingredients. The use of a reinforcing carbon black of optimum particle size in conjunction with high crosslink density maximizes the resistance to explosive decompression. ... 

Hydrogenated nitrile mbbers were evaluated for use in seals and hoses for automotive air conditioning systems. Studies were made of the resistance of these materials to hydrofluorocarbon refrigerants and polyalkylene glycol and mineral oil based lubricants, and permeation resistance, explosive decompression and low temperature performance characteristics were investigated. Designed experiments were undertaken to study the effect of compounding techniques on permeation and explosive decompression. 4 refs. 

In addition to exposure to extremes of temperatore, oil-field elastomers must perform satisfactorily when exposed to high pressure. The primary problems related to high-pressure service are extrusion and explosive decompression. Parts are rated for differential service pressures in 34.48 MPa increments up to 137.9 MPa. A comparison of the extrusion resistance of various elastomers is given in Table 16A.2. 

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