A comprehensive guide to understanding sanitary control valves

Basic knowledge of sanitary control valves
Sanitary control valves are critical components in sanitary processing applications where the cleanliness and integrity of the media are critical. They are commonly found in the food and beverage, pharmaceutical, biotechnology and cosmetic industries, among others. The following are the basic principles of sanitary control valves:

Purpose
The primary function of a sanitary control valve is to regulate the flow of liquid or gas through a pipeline to maintain process conditions within required parameters. They ensure that media (liquid, gas or semi-solid) flowing through the system can be started, stopped and regulated safely without causing contamination.

 

 

design
Sanitary control valves are designed to meet strict hygiene standards. They are usually made of stainless steel or other non-reactive, corrosion-resistant materials that are easy to clean and disinfect. Smooth surfaces, eliminating dead corners and minimizing gaps are also key design elements to avoid product buildup and bacterial growth.

Cleaning and sterilization
Sanitary control valves are designed to be easily cleaned and sterilized. They must be able to withstand processes such as clean-in-place (CIP) and steam-in-place (SIP) to ensure the entire system remains free of contamination.

Operation
Sanitary control valves can be manually or automatically operated. Manual operation involves using a handwheel or lever to control the valve, while automatic valves use electric or pneumatic actuators that can be controlled remotely and integrated into the process control system.

seal
Sanitary control valves typically use high-purity elastomer or plastic seals to prevent leakage and contamination. These seals must be able to withstand regular cleaning and disinfection processes.

comply with standards
Sanitary control valves adhere to strict industry and government standards to ensure they meet all necessary requirements for sanitation and safety. This may include 3A hygiene standards, FDA requirements and European Hygienic Engineering and Design Group (EHEDG) guidelines.

type
There are different types of sanitary control valves including ball valves, butterfly valves, diaphragm valves and check valves. The type chosen depends on the specific application and its requirements.

Understanding these basics will aid in the selection, operation and maintenance of sanitary control valves. Every application has specific requirements, so it's important to work with a knowledgeable supplier or engineer like THINKTANK when selecting a sanitary control valve.

Key components of sanitary control valves
Sanitary valves are designed and manufactured to ensure that process media are not contaminated. The following are the key components of a sanitary control valve.

valve body
The main body of the valve is the outer shell, which is usually made of stainless steel or other hygienic materials. It is usually designed to be easy to clean and disinfect.

Actuator
This is the component that physically moves or controls the valve. It can be manual (hand-operated), electric or pneumatic (pneumatic). The actuator is mounted on the valve stem, which in turn controls the opening and closing of the valve.

valve disc or valve plug
This is the part of the valve that directly regulates the flow of the medium. When the actuator moves the valve stem, the plug or disc opens or closes the valve, depending on the design.

Dry
The valve stem connects the actuator to the valve disc. It transmits the movement of the actuator to the disc, allowing the valve to open or close.

seat
This is the surface that the valve disc seals against. When the valve is closed, the disc contacts the seat, forming a seal that blocks flow. It is also designed to be easy to clean and reduce contamination.

Seals and Gaskets
They are used to ensure a tight fit between the different parts of the valve and prevent leaks. They are typically made from high-purity elastomers or plastics that can withstand the sterilization process.

end connection
These are the parts of the valve that connect to pipes or equipment. Among sanitary valves, these valves are usually designed to be easily attached and disassembled for cleaning. Common end connection types are clamps, welds, threads, and flanges.

hat
This part houses the valve stem so that it is properly aligned with the actuator and valve disc. It is also responsible for preventing leakage in the space where the valve stem leaves the valve body.

Each of these components plays a vital role in the operation of a sanitary control valve and can be designed to meet specific sanitary standards such as 3A, EHEDG, FDA or other standards.

How to operate sanitary control valve
Sanitary control valves are very similar to other control valves in that they operate by manipulating the flow of media (such as liquids, gases, or slurries) in the system, but they do so under strict sanitary conditions. They are designed to meet high standards of cleaning and sterilization, and their operation involves a combination of manual, automatic or semi-automatic components.

Here is a general overview of how sanitary control valves operate:

signal reception
Operation of a sanitary control valve usually begins with receiving a signal from the control system. The system monitors process conditions such as flow, pressure or temperature. When the system determines that a change in flow is needed based on these parameters, it sends a signal to the valve actuator.

Actuator response
Once the signal is received, the electric or pneumatic actuator is activated. It moves to adjust the valve's position. The actuator is usually connected to the valve stem, which in turn is connected to the valve's disc or plug. The movement of the actuator determines whether the valve opens, closes or partially restricts flow.

flow regulation
The valve disc or valve plug in the valve body is the component that physically interrupts or allows the flow of media. When the actuator is activated, it moves the valve stem and disc/plug. If the actuator moves the plug to the open position, media flow is allowed. If it moves to the closed position, flow stops.

seal
When the valve is in the closed position, the valve disc or valve plug forms a seal with the valve seat, effectively preventing the flow of media. Valve seals and gaskets also play a vital role in preventing leaks and ensuring system hygiene.

Return to normal operation
Once the necessary adjustments have been made and the desired process conditions have been achieved, the control system sends a signal to the actuator to return the valve to its normal operating position if necessary. This could mean fully open, fully closed or adjusted to a specific level of restrictions.

Cleaning and sterilization
Sanitary control valves are usually designed to be easily cleaned and disinfected without disassembly. This can often be accomplished through clean-in-place (CIP) or steam-in-place (SIP) procedures, which circulate cleaning and sterilizing agents through the system to ensure the system is free of contamination.

It is worth noting that the operating details of sanitary control valves may vary depending on the type of valve (ball valve, butterfly valve, diaphragm, etc.), the type of medium being controlled, and the special requirements of the system. The valve is installed.