When it comes to piping systems, especially in the food and brewing industry, a lot of people think about folding fittings, valves and pumps. Meanwhile, there are elements without which normal operation of the equipment is simply impossible. One of these elements is a stainless steel plug with internal thread. At first glance, it may seem like a simple detail, but after twenty years of work with pipelines and grub, I have discovered that the very cost of choosing the right plug often determines the reliability of the entire system.
What is a stainless steel plug with internal thread and is it needed
Basically, plug with internal thread is a metal “cuff” that is screwed onto the end of the pipe or a fitting with an external thread and hermetically blocks the flow of gas. It allows you to close the connection, protect the system from obstruction and avoid the flow.
It is important to understand that not every plug is suitable for grub and beer brewing. The material, the precision of the carving, the internal coating and the method of surface processing are of great importance. In my practice, the best results are obtained with plugs made from AISI 304 steel. This steel has excellent corrosion resistance in highly voluminous environments and is easily subject to sanitary processing. Moreover, it is remarkably inexpensive.
Design features
The internal thread of the plug can exactly match the external thread of the pipe or fitting. Failure to apply pressure can lead to problems with sealing. Here I can think of one incident at a craft beer production plant: the installer confused the thread of the plug with the thread of a standard fitting, and at the first start of the system under a pressure of 2 bar, the plug began to leak. I had to disassemble the kit, change parts and check everything I had gathered. From then on, we will mark all plugs by thread type and diameter.
Another important feature is the shape of the plug. The most commonly used models are cylindrical or lightly finite. The final form is easier to tighten and ensures a tight fit to the carving without additional stretchers. For cylindrical plugs, sanitary sealing rings made of grub silicone are sometimes used to enhance the tightness.
Advantages of stainless steel plugs
In practice, I see a number of key advantages of such plugs, such as making them indispensable for grub and beer brewing.
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Corrosion resistance. In the middle of the plug there are often aggressive substances: wort, malt concentrates, and other ingredients. AISI 304 steel copes well with acids and acids, which ensures durability
