viot web store FAQ section

Vacuum pump oil can be added through the hole on the pump after removing the exhaust muffler on top of the pump. Watch the oil level from the sight viewing glass on the front of the pump. make sure to put back the muffler after adding the oil. This applies to all VIOT pumps and other brand names pumps of the similar configuration.

Manifold gauge set is a key tool to every HVAC field service person. These factors should be considered before purchasing one: 1: what refrigerant and pressure range it covers? Most refrigerants(R22, R134a, R12, R502, R404 R407) have a working pressure around 150 PSI, while the R410a system have a much higher pressure range. You may consider getting a R410a manifold for the R410a systems, and another set for the others. 2: Hoses, how long you need? 3 feet is usually enough for car AC systems, you need 5ft for other AC systems. longer the hose you may reach a little farther, but it may hold/loose more refrigerant each time checking a system. 3: Gauge faces, bigger ones are easier to read. 4: Gauge body material, brass is heavy, aluminum block is lighter and stronger. 5: Hose fittings: are they EPA applied, self-closing fittings. The open-ended hose fitting give you surprises every time you disconnect it, if nothing more serious. 6: O-ring seals, Teflon is 10 time stronger and durable than rubber. 7: Working pressure and burst pressure. go with the higher ones if available. 8: R410a manifold: pay attention to the hose fitting size. 2 system port size available and so are the manifold hoses. you may need 2 set of hoses or adapter to access all system.

We are an Illinois based company, serving HVAC profession tools for over 10 years. from the campus town Champaign. We have a web store at: http://viot.us/HVAC, we also have a EBay store by the name VIOT_HVAC, you may check with EBay and see our feedbacks there. we are a Top-Rated Power Seller with the great standing in the web space for HVAC Service tools.

WVS5 and WVS5b have the same pump, the difference is how the vacuum get controlled for different applications. WVS5 has a vacuum switch which turns off the pump when the vacuum gets to the set level. It is designed for a workshop application, where the system is leak-proof and the intake air is dry so the pump will shut off and kick in at the set vacuum levels. However, a small leak in this system may cause the pump flip on and off frequently which may add ware to the pump. WVS5b is modified by removing the vacuum switch with a vacuum regulator, which can work on a leaky system like a milker machine, the pump will run continuously, the vacuum level is controlled by the regulator to a max level as you wish (bellow -25 inch Hg). The regulator is a functional safety valve to make sure the vacuum level never exceed the set level. WVS5b can tolerate moisture in the system as well. Both vacuum systems have the same vacuum tank. Yes, they can have the similar adjustable range. they have a mini-muffler on the exhaust port of the pump, it works well in reducing the noise level. you may not hear much of the noise if you are 10 feet away from it.