Vacuum Pumps, where to add the oil?
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 Gauges, what I need to know before buying a set?
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.
where is VIOT located?
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.