RParts has these unusual valves manufactured just for us. We call them "Base Valves". They are designed to stand upright and are bolted in place using a threaded bolt hole in the bottom. They operate in the same way as a conventional service valve, providing three-way refrigerant access and shut-off. We use them as part of our DIY kits to provide an easy way to isolate the compressor unit from the tube set and evaporator.