Introduction:
A tank bottom diaphragm valve is a special valve installed at the bottom of a container (such as a storage tank, reactor, or fermenter). Its core is to separate the valve body cavity from the actuator through an elastic diaphragm, thereby realizing the opening/closing of the medium and flow control. It is widely used in industries with strict requirements for hygiene and sealing, such as pharmaceuticals, food, dairy products, and bioengineering.
Core Structure and Working Principle
The core components include the valve body, resilient diaphragm, valve stem, and actuator (manual/pneumatic/electric).
During operation, the valve stem drives the diaphragm to move up and down: when the diaphragm presses down against the valve seat, the valve closes, blocking the flow of media; when the diaphragm moves up away from the valve seat, the valve opens, and the media flows out from the bottom of the container.
As a critical sealing component, the diaphragm completely isolates the valve core from the media, preventing contamination of the media by the valve stem, actuator, and other components, while also preventing the media from corroding the internal structure of the valve.
Core features and advantages
Excellent hygiene: Only the valve body and diaphragm come into contact with the media, eliminating dead zones and residues. It meets GMP, FDA, and other hygiene standards, making it suitable for aseptic production environments.
Reliable sealing performance: The diaphragm fits tightly against the valve seat, resulting in extremely low leakage. This effectively prevents media leakage and external contamination, making it particularly suitable for toxic, corrosive, or high-purity media.
Suitable for harsh operating conditions: The valve body can be made of corrosion-resistant materials such as 304/316L stainless steel, and the diaphragm can be made of EPDM, PTFE, silicone rubber, etc., withstanding acid and alkali conditions, high temperatures (typically -20~150℃), and high pressure (typically 0.1~1.6MPa).
Easy maintenance: The structure is relatively simple, and the diaphragm is easy to disassemble and replace, requiring no complex maintenance, reducing maintenance costs and downtime.
Main types and applicable scenarios
Manual tank bottom diaphragm valve: Simple structure, low cost, suitable for small to medium scale production and manual flow control scenarios (e.g., small food ingredient tanks, laboratory reaction vessels).
Pneumatic tank bottom diaphragm valve: Fast response, high degree of automation, supports remote control, suitable for large-scale production lines and continuous operation scenarios (e.g., pharmaceutical aseptic mixing tanks, dairy milk storage tanks).
Electric tank bottom diaphragm valve: High control precision, allows for fine-tuning of flow, suitable for scenarios with strict flow control requirements (e.g., vaccine raw material storage tanks, cosmetic essence storage tanks).
Aseptic tank bottom diaphragm valve: Valve body made of 316L electropolished material, diaphragm conforms to USP Class VI standard, supports in-line sterilization (SIP), suitable for aseptic production scenarios in pharmaceuticals, vaccines, and bioengineering.
Typical Application Industries:
Pharmaceutical/Vaccine Industry: Bottom discharge control in aseptic mixing tanks, fermenters, and bulk solution storage tanks to ensure drug sterility.
Food/Dairy Industry: Discharge from beverage mixing tanks, yogurt fermentation tanks, and edible oil storage tanks to prevent cross-contamination.
Biotechnology Industry: Media transport in cell culture reactors and culture medium storage tanks to prevent microbial contamination.
Chemical/Cosmetic Industry: Discharge from corrosive raw material storage tanks and essence storage tanks, ensuring resistance to corrosion from special media.
