Purchasing Guide: Valves

Valves perform a vital function in the lab of opening, closing, and controlling the flow of fluid through a pipe or tubing. Valves come in a grand array of sizes, materials of construction, controls, and precision. Simple valves are used to open or close the tube for flow. More sophisticated valves can regulate the amount of flow by controlling the size of the aperture through which the fluid is allowed to pass. Some computer-controlled valves can deliver high accuracy and precision of flow for experiments like multi-flow reactors. For a list of valve manufacturers, see our online directory: LabManager.com/valve-manufacturers

8 Questions to Ask When Buying Valves:

1. How will the fluid’s properties affect the valve specifications needed?
2. What is the size of the pipe or tubing?
3. What is the pressure of the fluid?
4. What level of flow control is required?
5. How accurately and precisely does the flow need to be controlled and delivered?
6. What valve material is needed to be compatible with the fluid?
7. How many valves are needed?
8. Do you need a backup valve in case of failure?

Three Types of Gas Valves

There are three types of gas valves used in laboratories: gas needle, gas fine needle, and gas ball. Needle and fine needle valves are designed to offer flow regulation at low rates where fine, precise control is needed. Ball gas valves, on the other hand, don’t offer flow rate regulation; they only block or allow gas to pass through. Which type best suits your application?

Safety Tip

Always turn gas valves off when not in use. Even if the equipment is sitting in a fume hood, don’t assume that the hood is venting all the gas. Some of it may be leaking into your lab, which can pose health and safety hazards.