In this new article, we list the stainless steel accessories and safety valves used in tank setups, focusing on their functionality and utility. For better understanding, we can carefully observe the image above which shows a fully equipped stainless steel tank and provides
a complete list of generally used stainless steel accessories and valves, along with their positioning in the storage tank.
STAINLESS STEEL MANWAY DOORS AND STAINLESS STEEL MANHOLES
Stainless steel manway doors and stainless steel manholes are critical installation’ components in many industrial sectors, particularly those managing liquids or chemicals, as well as the food and pharmaceutical sectors.
Stainless steel manways are located on the lateral-bottom sides of tanks and containers; they are used for their inspection, washing and partial or complete emptying.
Stainless steel manholes are installed on the top of storage tanks and, as stainless steel manways, are available in various models with different features.
Some stainless steel manholes’ models have vent holes or anti-retention covers; the upper manhole with glass allows the inspection of the product processing inside the tank.
Stainless steel manways and stainless steel manholes must ensure an hermetic closure in order to prevent contamination and product loss; their structure must withstand the pressure exerted by the product stored in the stainless steel tank, and the material they are made of must be suitable for the technical needs of the application (e.g., AISI 304 or AISI 316 stainless steel).
To further explore the topic, we recommend reading our article: “Stainless Steel Manways and Manholes: Buying Guide.”
SAFETY VALVES
Here below, we describe the functioning of the main safety valves used in tanks, that are the discharge valve, vacuum valve spring loaded, double-action reflief valve, and bunging devide.
DISCHARGE VALVES
The discharge valves are installed at the top of stainless steel tanks.
They are used to stabilize internal pressure in case of overpressure situations according to the production process specifications, thus preventing damage to the tank and its accessories.
They can be categorized into free discharge valves and angle-body regulating valve.
Free discharge valves activate in overpressure scenarios, allowing gas to flow out and reduce internal pressure and temperature of the stainless steel tank. Angle-body regulating valve operates on the same principle of free discharge valves, but they direct fluids into a dedicated recovery conduit.
Both types of discharge valves are available as adjustable version – spring relief valve (where the user can set the opening pressure) and standard non-adjustable versions.
VACUUM VALVE SPRING LOADED
A vacuum valve spring loaded, protects tanks, cisterns, and installation’ systems from negative pressure (lower than atmospheric pressure). The vacuum valve spring loaded operates by constantly monitoring the differential between atmospheric pressure and internal tank pressure.
If this value falls below the operational differential of the vacuum valve spring loaded, or the user-set differential in adjustable vacuum valves, the valve will open and generate an air suction into the tank.
The vacuum valve spring loaded is fundamental in order to prevent damage from vacuum conditions, such as tank deformation or contraction (implosion).
DOUBLE-ACTION RELIEF VALVE
The double-action relief valve balances the internal tank pressure, preventing it from falling below atmospheric pressure (depression) or rising above a certain limit (overpressure), thus protecting the tank and its accessories from potential damage.
These safety valves are available in adjustable (for overpressure only) and standard non-adjustable versions too.
BUNGING DEVICE
A bunging device is a gas safety valve that opens when the internal tank pressure exceeds the user-set value. When activated, the gas in the tank escapes into a glass cup that surrounds the valve, restoring the proper pressure level inside the tank. For correct operation, the glass cup must contain water.
The bunging device also prevents oxygen from entering the tank, allowing for anaerobic fermentation, that is created without air.
As it is quipped with a pressure gauge, the bunging device allows continuous monitoring of the tank’s internal pressure.
Bunging devices are frequently used in tanks and fermenters for the producton of beer, sparkling wine, and any beverage or liquid that generates fermentation/gas.
OTHER ACCESSORIES FOR SETUP CIP-TOP TANK SAFETY VALVE
The cip-top tank safety valve is a combination of safety devices for overpressure, vacuum, CO2 discharge recovery and tank cleaning. This accessory is installed at the top of the tank; overpressure and vacuum values can be user-adjusted according to system needs.
Tank cleaning is done via a washing ball (which can be a rotating washing ball) installed at the CIP-TOP rod base, that will be inserted into the stainless steel tank or cistern.
STAINLESS STEEL ROUND MANHOLE WITH FULL SIGHT GLASS AND PERIPHERAL CLOSINGS
The stainless steel round manhole with full sight glass and peripheral closings is installed at the top of the tank. Thanks to the vision through the glass, this accessory allows you to inspect the working process of the product that take place inside the tank. It is used in particular to observate the fermentation process.
SAMPLING COCKS AND LEVEL COCKS
The sampling cock is a rod (made of glass or plexiglass) installed on the side wall of the stainless steel tank. It’s connected at its upper end to an upper level porter tap, and at its lower end it is connected to a lower level porter tap.
The level cock measures the liquid level inside the stainless steel tank or stainless steel cistern.
In order to permit the collection of the fluid from the stainless steel tank or the stainless steel cistern, the lower level porter tap, connected to the rod at its upper part and featuring a drain hole at the lower part, can be opened to draw a product sample.
SAMPLING COCK
A sampling cock is a stainless steel faucet installed on the tank or cistern’s side wall. This stainless steel accessory allows for sample collection of the liquid inside the stainless steel cistern in order to monitor the processing stages.
There are various types of sampling cock, for example those with hose fittings, sampling cocks with curved fittings, sampling cocks with GAS threaded connections, and sampling cocks with DIN connections.
In the Accessories section of our catalogue are listed the most used sampling cocks for tank setups.
BUTTERFLY VALVE
The butterfly valve is one of the most commonly used types of valves for regulating fluid flow.
It is called “butterfly” because its operation is based on a closing disc mounted on a central stem, and this shape resembles of a butterfly with open or closed wings. The opening and closing of the valve is achieved by rotating the stem on which the butterfly is mounted. The valve is open when the butterfly is positioned diagonally or perpendicularly to the diameter of the tube, thus allowing the fluid to flow, and is closed when the butterfly is positioned parallel to the diameter of the tube, because the butterfly closes the passage and stops the flow of fluid.
BALL VALVE
Ball valves are used in many types of installations, such as food, chemical and hydraulic plants, to manage the flow of liquid and semi-liquid products, allowing them to be closed, opened and reduced.
It is equipped with a spherical shutter with a central cylindrical hole, commonly called “ball”, and depending on the position of the central hole in relation to the axis of the valve, the closing, opening or partitioning of the fluid flow is achieved.
The valve is open and allows fluid to pass when the central hole of the ball is positioned in line with the valve axis, while the valve is closed and stops the flow of fluid when the central hole of the ball is positioned perpendicular to the axis of the valve.
SIGHT GLASS
The sight glass is a stainless steel accessory that allows you to create a transparent window (glass) through which you can visually inspect the flow of fluids inside an equipment, or to safely and reliably monitor the production process within a tank, or a tank.
For more information about stainless steel manways, stainless steel manholes, stainless steel accessories and sight glasses, you can view our products’ catalogue or you can contact us by phone on +39 0421-679996 or by mail at export@venetaacciai.it
FAQ
What are the stainless steel manway doors and manholes used for?
The stainless steel manway doors are placed on the lower side of the tanks and stainless steel cisterns and serve for inspection, washing and total or partial emptying. The stainless steel manholes, on the other hand, are installed on top and allow visual inspection and can be equipped with glass or openings to allow the installation of stainless steel protection valves.
What are the suitable safety valves for a stainless steel tank?
Here is a list of some safety valves that can be installed on a stainless steel tank or cistern:
- Discharge valve: free discharge valves and angle-body regulating valves.
- Vacuum valve spring loaded.
- Double-action relief valve.
- Bunging device.
What is the discharge valve used for?
The discharge valve is used to stabilize the internal pressure of the tank in case of overpressure, thus preventing damage to the tank or the tank and its accessories installed. Free discharge valves and angle-body regulating valves are available on the market, both in the adjustable version and in the non-adjustable version.
What is the vacuum valve spring loaded used for?
The vacuum valve spring loaded serves to protect the tank or cistern on which it is installed from the negative pressure that may occur inside. The use of a vacuum valve spring loaded avoids damage caused by the vacuum, such as tank deformation and contraction (implosion).
What is the double-action relief valve used for?
The double-action relief valve makes it possible to balance the pressure inside the tank, preventing both vacuum and overpressure, preserving the integrity of the stainless steel tank, the stainless steel accessories installed on it and the stainless steel pipes connected to it.
What is the bunging device used for?
The bunging device is a gas safety valve that allows to maintain an optimal pressure inside the tank or cistern. When the pressure inside the tank exceeds the value set by the user, the bunging device is activated allowing the excess gas to escape. The bunging device is often used in the production of beer, sparkling wine and other fermented beverages. It is equipped with a pressure gauge and therefore allows you to constantly monitor the internal pressure of the tank.
What is the CIP-TOP valve?
The CIP-TOP valve is a device that allows you to manage overpressure, vacuum, CO2 channelled discharge recovery and tank cleaning. It is a combination of safety devices. It is installed in the upper part of the tank or cistern, and the overpressure and vacuum values can be adjusted by the user according to the installation needs.
What is the stainless steel round manhole with full sight glass and peripheral closings?
The stainless steel round manhole with full sight glass and peripheral closings is installed in the upper part of the tank. Through the glass allows to observe the processes of processing the product that take place inside the tank or tank. It is particularly used to monitor the fermentation process.
What is a level cock?
The level cock is a glass or plexiglass rod connected to two taps (upper level holder and lower level holder), which allows you to measure the level of liquid in the tank. Through the lower level tap it is also possible to take liquid samples for analysis and monitoring of the product.
What is a sampling cock?
The sampling cock is a stainless steel tap that is installed on the side wall of the tank. It is used to take samples of the product contained in the tank or cistern, in order to monitor the stages of the process of processing the product. There are various types of sampling cocks and with different attachments for installation on the stainless steel tank.
What is the difference between a butterfly valve and a ball valve?
The butterfly valve allows the regulation of the fluid flow through a closing disc mounted on a central stem (called butterfly). The opening and closing of the butterfly valve is achieved by rotating the stem on which the butterfly is mounted.
The ball valve allows flow regulation through a spherical shutter with a central cylindrical hole, commonly called „sphere“. Depending on the position of the central hole with respect to the valve axis, the fluid flow is closed, opened or partitioned.
What is the flat sight glass used for?
The flat sight glass is a stainless steel accessory that allows the visual inspection of processing processes inside a tank or equipment. It allows to create a transparent window so that the operator can monitor consistency and quality of the product during processing.