Thermocouple Working and Types. Tachometer Working and Types. Rotameter Working and Types. Cascade Control and Ratio Control. Feed Back and Feed Forward Control. Venturi Meter versus Orifice Meter. Orifice Meter Structure and Working. Venturimeter Working Principle. Breather Valve Working Principe October 6, Breather Valve Working Principe. More:- Chemical Engineering World. Instruments Thermocouple Working and Types 29 Oct, Instruments Tachometer Working and Types 16 Oct, Instruments Rotameter Working and Types 15 Oct, Instruments Venturimeter Working Principle 22 May, In sealed containers there is a pressure change ranging from 1.
It should be noted that these tests were run on rigid wall containers, and that low-setting valves on plastic containers with flexible walls will probably not open as often under the same conditions. There are only a few locations in the world other than Tucson where greater diurnal temperature variations occur. Therefore, under worldwide storage conditions, valves with a 0.
There are places in the world where as much as 0. However, high humidity tends to limit temperature variations Fig.
For each descent from Higher or lower valve settings will not substantially vary the amount of moisture gain per descent. Therefore, the amount of desiccant needed will, in part, depend on the number of airlifts anticipated.
It has been noted above that in ground storage, each time a container must breathe it will take in as much as 0. Keeping the above factors in mind, we see that a Breather Valve, properly selected and used in conjunction with adequate desiccant, can provide years of moisture protection in a lightweight, low cost container.
The Breather Valve must perform two functions: limit the amount of moisture that can enter the container, and protect the container itself from excessive pressure or vacuum differentials. Therefore, the ideal valve should remain sealed except for during airlift or under extreme temperature changes, but when open should have sufficient flow to relieve air pressure as fast as it builds up.
In order to select a valve which will adequately protect the container against excessive pressure or vacuum, we must know the following:. This figure Fig.
For instance, the container pictured in Fig. For this reason, a pressure setting somewhat higher than the vacuum setting is often specified to provide a sufficient differential without overstressing the container.
However, too great a differential more than 3 psi between the pressure and vacuum settings can cause valve design problems and increased cost. If a differential greater than 3 psi is required, 2 one-way valves should be used. It should be remembered that a total differential in sealing pressures of 1 to 2 psi will provide more than adequate moisture protection worldwide.
It is essential to know how much air, in cubic feet, will be inside the container. This may be calculated by subtracting the volume of the contents engine, missile, etc. IATA also specifies Par. To avoid two breathing valve operation and increase the risk of failure at the same time, usually the two breathing valve suction and discharge pressure in gradient type design, a working normally, the other is spare.
Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Email: [email protected]. How does the breather valve work? This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world. I would like to know a little more about lessons learned from not using this standard correctly.
Your email address will not be published. Save my name and email in this browser for the next time I comment. This document covers the requirements for the determination of design pressure and design temperature of the equipment like pressure vessels and piping that are used in petroleum refineries, Aluminum and Stainless steel are two widely used materials in various industries.
Wherever lightweight is a requirement, aluminum seems to be a good metallic option. Stainless steel is widely used as Skip to content. Typical Breather Valves.
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