Vacuum-steam-pressure-test

Vacuum-Steam Pressure Test 106 is briefly described in Vol 4, p D1098-R... 

Vacuum-Steam-Pressure Test. A special aging test which has been used successfully in the USA to accelerate aging to produce the effects of 6-month tropical exposure on certain types of sealed fuzes. It is primarily a development test which can be used during production The test consists of subjecting bare fuzes to 1000 fifteen-minute consecutive cycles in a vacuum-steam-pressure environment. The 1000 cycles takes about 10 days of continuous running time. The basic cycle consists of temperature-humidity cycling superimposed on pressure cycling in a test chamber with a salt laden atmosphere. Representative curves of temperature and pressure are shown in Fig 1... 

Temperature and Humidity Cycling Test for Use in Etevelopment of Fuzes Vacuum-Steam-Pressure Test for Use in Development of Fuzes... 

Military Standard. "Fuze and Fuze Components, Environmental and Performance Tests for MIL-STD-331 (1966 1967) Class 100. Laboratory Tests - Jolt (101) Jumble (102) Forty-Foot Drop (103) Transportation Vibration (104) Temperature Humidity (105) Vacuum Steam Pressure (106) Salt Spray (Fog) (107) Waterproofness (108) Rain Test (Exposed Fuze Storage) (109) Fungus Resistance (110) Five-Foot Drop (111) Extreme Temperature Storage (112) Thermal Shock (113) Rough Handling (Packaged)... 

A column vacuum was produced with the eductor, and the operating pressure set to the desired test conditions. Water and steam flows were initiated, and the column was allowed to reach steady state. Steady state was determined by careful monitoring of column temperatures at the reboiler, mid-column, and top of column and confirmed by analysis of vapor and liquid samples drawn from the column sample ports over a 2- to 3-hour period. The height of an equivalent theoretical plate (HETF) of the packing was 19 in., as calculated from vapor and liquid sample compositions. 

This demonstration plant will normally operate at a first-effect boiling point of 250° F., a last-effect boiling point of 120° F., and a discharge sea water concentration factor of 4. The primary control of the process is accomplished by automatic control of steam flow rate, sea water flow rate, and last-effect vacuum. No control is needed for temperature or pressure in the individual effects and heat exchangers, since these achieve their own levels, influenced only by the proportioning of the equipment. The demonstration plant is rather heavily instrumented to permit close surveillance of operating conditions and carrying out of special tests. 

Coils inside pressure vessels may be subjected to the internal pressure of the vessel acting as an external pressure on the coil. In addition, steam coils should be designed for full vacuum or the worst combination of external loads as well as the internal pressure condition. The coil must either be designed for the vessel hydrotest, externally, or be pressurized during the test to prevent collapse. 

A.212. This section should describe the design bases for qualification of components to resist such environmental factors as vibration, thermal expansion, radiation, corrosion, dynamic effects, mechanical loadings and high pressure, high temperature, humidity, water, steam, chemicals, low temperature or vacuum. Qualification tests and analyses that have (or will be) performed should be described. 

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