QUESTION: I have a friendly competitor. We talk from time to time about business. I share my troubles and successes and he shares his. He recently brought up the idea of buying an ‘oil separator’ and a ‘silencer’ for his truck. He told me it would make his pump run quieter, but is this true? What is a ‘silencer’ and how does it fit in the scheme of things?
Danny Bishop, Portland, Ore.
ANSWER: There are many optional accessories available for vacuum systems. Let’s talk about those accessories. These items are not absolutely necessary for the safe operation of your vacuum system, but they will improve and extend the life of your system:
Pre-filter: The basic operating system has a primary shut-off on top of the tank, followed by the secondary moisture trap, and then the next item in line is the vacuum pump. The pre-filter is set in line after the secondary and before the pump. In a sense it is a ‘thirdary.’ It can act as a final line of protection to your pump. The pre-filter catches whatever is possibly passing through your secondary before it reaches the pump. Inside, the pre-filter is a 300-micron stainless steel screen designed to catch the smallest waste.
Oil separator: The oil separator does exactly what its name implies. It catches exhaust oil from the pump, similar to the oil catch muffler. Its main drawback is that it offers no real muffling of the noise involved in pump operation. Manufacturers of oil separators advise buying a ‘silencer’ to work in tandem with the separator.
Silencer: This is a device for cutting down the noise of your vacuum system. It is generally installed in line with the oil separator and reduces the operating noise level. I don’t have a lot of experience with these components, but truck owners I respect have told me having an oil separator and silencer, along with the oil catch muffler, has made a big difference in the noise. Some systems are noisier than others, so it’s a personal decision if you want to use these items.
Exhaust interceptor: This is another cousin to the oil catch muffler. It is installed in line after the oil catch muffler. In one sense, it is another oil catch muffler. It reduces smoke and noise, while at the same time capturing leftover oil that may be coming from the pump.
Deodorizer: The deodorizer system masks offensive exhaust from the vacuum operation. It is intended to make the work more tolerable for your drivers and save passersby from getting a whiff of those odors. The deodorizer features an aluminum box filled with computer-designed balls and attached right after the oil catch muffler. A diluted, scented deodorizing concentrate is added and the vacuum tank exhaust passes through the box, covering up odors.
These five add-ons do not necessarily prevent major problems in your vacuum system, but they can add a measure of protection and efficiency, as well as make the environment more pleasant for the technician and the public.
Explain these two valves
QUESTION: What’s the difference between a ball valve and a knife-gate valve?
Rick Cuthbert, Omaha, Neb.
ANSWER: The answer to your question is found in the names of these two products. A ball valve has a handle connected to a ball and that ball opens and closes a system. The knife-gate valve operates like a guillotine. When the valve is open, the knife is up. To close the system, the operator pulls a handle that lowers the ‘knife’ like a guillotine and seals the system. Both types of valves work well, but the knife valve can sometimes build up residue, become stuck or no longer seal completely.
