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Alfa Laval Sanitary Sampling Valve

How does a sampling valve work?

Alfa Laval sampling valves enable the operator to extract a representative portion of the process liquid for analysis to ensure quality control. The valves are operated either by manual handle, by pneumatic actuator, or by a combination of manual handle and pneumatic actuator. For sterile sampling, a hypodermic needle is inserted into a rubber membrane plug to draw the process liquid for evaluation.

SB Carlsberg Flask

How it works

When the wort is well aerated, the yeast culture is introduced aseptically through the membrane fitting using a 150-200 ml syringe. You can also transfer dry yeast culture to the flask through the empty filter housing. If you need larger quantities of yeast, the lid can be dismantled and the culture poured into the flask. This procedure, however, requires a sterile environment and the highest degree of precaution.

The transfer of pure yeast culture into the propagation plant should take place at the “high kräussend” stage under aseptic conditions and requires a sterile air supply to the breathing filter. Recommended sterile air supply during inoculation into yeast propagation plant is 2 bar and must not exceed 5 bar (72.5 psi) at any time. The yeast culture can be pressed from the flask into the inoculator once the membrane sample valve on the lid of the Carlsberg Flask has been connected to a sample device on the receiving vessel (the inoculator).

The connecting hose, membrane sample valve and all other connections must be thoroughly sterilized with either alcohol or steam before transfer. Between operations, the valve can be sealed with alcohol, which can then be flushed out with sterile air prior to use.

When you have made the connection and you are ready to inoculate, we recommend first opening the sterile air supply, then the membrane sample valve on top of the flask and finally the sample device on the inoculator.

When the culture has been transferred (indicated by a bubbling noise in the inoculator), we recommend continuing with the air supply for another couple of minutes to make sure that all of the yeast culture has been transferred.

Finally, the sample device on the receiving vessel and the membrane sample valve on the Alfa Laval SB Carlsberg Flask can be closed, effectively closing off the air supply.

After use, the flask needs to be taken apart and cleaned manually with normal detergents.

The Alfa Laval SB Carlsberg Flask consists of a cylindrical container with a flat bottom and top cover equipped with breathing filters, a membrane sampling valve for aeration and product transfer, and a micro sample port for aseptic introduction of pure yeast culture. During the transfer of pure yeast culture from the Alfa Laval SB Carlsberg Flask to the yeast propagation plant, it is important that all hose tails are safely fastened with hose clips.

The flask is filled with wort to the net capacity (approximately 80% of the total volume), sterilized using an autoclave, a gas burner or an electric hotplate. The flask is then placed in a refrigerator or a cold room to cool the wort to the desired working temperature. The cold wort is aerated through the membrane sampling valve connected to the aeration lance.

Yeast culture can be introduced aseptically through the membrane fitting with a syringe, or dry yeast culture can be transferred to the flask through the empty filter housing.

The breathing filter can remain attached to the flask during sterilization. However, if the breathing filter has been sterilized separately, it is important to reattach it while steam is still evaporating from the flask (at the end phase of the wort sterilization) so that the filter connection is also sterilized. The empty filter housing can be used as a funnel for transferring pure dry yeast culture to the flask.

The cold wort is then aerated through the membrane sampling valve connected to the aeration lance. It is important to use sterile air. For safety reasons, it is also recommended to feed the wort through a filter mounted ahead of the membrane sampling valve.

Air supply and flow should be moderate to avoid foaming. It is important that foam does not come into contact with the breathing filter because it may block and damage the filter.

The easiest way to determine the right conditions for the air supply as well as the time needed for aeration (less than 10 minutes) is to test with the flask lid open. Note that you cannot use the yeast culture from these tests.

SB Membrane Sampling Valve

Operating principle

The valve is available with three different types of connection: tank, pipe and threaded. They operate on the same principle. Before the valve is opened, the closure should be placed on the upper hose connection. When the handle is turned to the horizontal position the sample starts to flow through the lower outlet. When the handle is turned back to the vertical position the valve shuts and the handle can be removed if required. Aseptic sampling can be taken using a special valve type with microport. If you remove the red cap, you can insert a hypodermic needle through a central channel into the membrane to take an aseptic sampling with the valve in the shut position. After sampling, flush the valve with water or alcohol. The valve can be sterilized using alcohol or steam.

As an option, Alfa Laval offers the Alfa Laval Steam Generator, which enables you to steam-sterilize where there is no permanent steam supply on hand.

Function and cleaning

1 Alcohol sealed valve

2 Alcohol is drained and the valve can be steam sterilized

3 Sample is taken

4 Valve is flushed with water/alcohol

5 Valve is sealed with alcohol

Technology

The valve consists of a valve body, actuator and membrane seal placed on the stem of the actuator, which works as a stretchable plug. The valve is sterilized in place with alcohol or steam. The membrane forms a seal directly against the product to ensure representative sampling, and give repeatable results safe from secondary contamination.

The valve is available in three different actuator designs:

• Manual - For manual activation
• Manual + Micro Port - For manual activation or sampling using a hypodermic needle to penetrate the membrane for sample taking.
• Manual + Pneumatic - For manual or pneumatic activation when the valve is connected to pipes for automatic sampling. The valve is then supplied with pipe outlet connections.

SB Micro Sampling Port

Aseptic sampling for microbiological control

To help ensure food and beverage safety, the sampling port features a straightforward hygienic design with minimal components makes collecting samplings mid-stream easy, convenient and accurate.

Versatile mounting

Direct mounting on the tank wall, pipe wall, or extruded pipe ends in either a horizontal position or vertically with the closing cap facing downwards makes the valve versatile and suitable for a broad range of applications and provides the flexibility needed to meet your sampling requirements.

Easy to clean

Hygienic design ensures optimum hygiene for representative sampling. When the port is located on the tank wall or pipe wall, the plug end that is flush with the wall is automatically cleaned during the routine Cleaning-in-Place (CIP) cycle. To minimize the risk of contamination, it is easy to sterilize the rest of the plug with alcohol before sampling.

How it works

The sampling port consists of a housing made as a socket for direct welding into the tank wall or pipework, a rubber plug which is positioned by a press screw, an o-ring, chain and a closing cap. These different types of sockets are mounted:

• Socket, Type T, is welded into a 25-mm diameter hole in a tank wall
• Socket, Type P, is welded onto a pipe wall and, thereafter, an 8-mm hole is drilled
• Socket, Type PC, is available for welding onto extruded pipe ends equal to 1” as well as DN25

To take a sampling, simply unscrew the closing cap and insert a one-mm hypodermic needle through the rubber plug.

Unique Sampling Valve

The Alfa Laval Unique Sampling Valve consists of a valve body, an actuator and membrane seal. The rubber membrane seal is placed on the stem of the actuator and acts as a stretchable plug. The valve body made of single piece of stainless steel eliminates need for welding. As such, this prevents pore formation and cracking in the welds, and subsequently risk of bacterial build-up.

Product range and accessories

The Unique sampling valves are available as single and double-seat with working pressures up to 6 bar and maximum temperatures of 130 °C. Membrane seals are made of FDA-approved EPDM or silicone. Choice of manual or pneumatic actuators is available. Other options include types of valve bodies, connections, actuators and accessories.

Sampling accessories

Alfa Laval has a broad range of high quality sampling accessories to provide users with comprehensive sampling solutions. These include non-return valves, quick couplings, pressure relief valve for steam sterilization and the Alfa Laval Steam generator, which enables you to steam-sterilize where there is no permanent steam supply on hand.