Know what are Breather Valves and Telescopic Slides All About

If you are yet to know what breather valves and telescopic slides are, this article lets you know them. Read on:

 

What are Breather Valves?

 

You can regard breather valves as particular types of relief valves specifically designed for tank protection. They are also called direct-acting pressure or vacuum relief valves.

 

Different types of breather valves include pressure only, vacuum and combined pressure or vacuum valves. They come with flanged outlets or vented to atmosphere.

 

Pressure or vacuum relief valves find extensive uses on bulk storage tanks. You can also use them on fixed roof tanks with floating covers to reduce evaporation loss.

 

The valves restrict excessive pressure or vacuum formation, which can unbalance the system or damage the storage vessel.

 

The control mechanism of the valves involves weighted pallets or springs that you can combine to provide the required pressure or vacuum levels.

 

It is a common practice to combine pallet and spring systems into one unit. For example, the pressure settings require a spring section while you use the vacuum settings in the pallet method.

 

Breather Valves Benefits

 

The primary purpose of breather valves is to prevent tanks from rupturing or imploding. You can regard the valves as a protection device mounted on a nozzle opening on the top of a fixed roof atmospheric storage tank.

 

In the absence of an opening or controlled opening, the likelihood of a fixed roof atmospheric tank rupturing under increasing pressure arises. The internal pressure increases due to the pumping of liquid into the tank or changing vapor pressure due to severe thermal changes.

 

A tank can implode or collapse during the pumping out procedure or thermal changes. For example, when the liquid level goes down, the vapor space pressure inside gets reduced to below atmospheric pressure. As a result, a collapse may occur.

 

However, it is not a cause to worry. You can prevent unwanted conditions by using a controlled opening on the tank.

 

A tank needs to breathe in to do away with the possibility of rupturing or imploding. As the valve facilitates breathing, it is called the breather valve.

 

What are Telescopic Slides?

 

Slides that extend telescopically from their closed position to a longer open part are called telescopic slides. They find frequent uses, especially for applications where access is required.

 

A typical example of such an application is the drawer, which has rolling ball bearings between the members. Usually, a drawer has a low movement force, even when loaded to its maximum load rate.

 

Types of Telescopic Slides

 

There are two types of telescopic slides– part extension and full extension.

 

Part extension slides consist of two rail members. They can extend to 75 percent of the closed length.

 

Full-extension slides comprise three rail members and can extend to 100 percent. The additional extension allows more access.

 

Linear slides have a short inner member or carriage within a closed track. Such slides find frequent uses in applications that guide instead of allowing access.

 

Usually, such slides operate more effectively when you place the load in the center of the carriage within the slide length.

 

If you use the slides in a cantilevered manner, you will see a significant reduction in the load capacity because of the short length of the carriage and the applied torque.

 

You also should know about the categories of the sliding motion. Typically, there are three sliding motion categories--caged ball bearing slides, recirculating ball bearing slides, and friction guides.

 

Caged ball-bearing slides have many rolling balls held by a cage or ball retainer between the members. It maintains ball bearings within the length of the slide’s tracks and allows smooth movement.

 

Recirculating ball bearing slides have rolling ball bearings that circulate within the recirculating ball carriage. The movement allows the carriage to travel any distance, which is governed by the length of the track.

 

Friction guides do not have rolling elements. Instead, the guides are made of advanced materials and surface treatments to provide sliding friction surfaces that can operate smoothly over a long period without necessitating lubrication.