Valve sizing and tuning for optimal control
Valve options
Choosing the right valve size is critical to ensuring that your process can achieve full-scale flow under your range of expected process conditions. A properly sized valve will give your mass flow controller or pressure controller stable control throughout the entire flow range.
When creating a quote, an applications engineer will used a specialized tool to select the best valve for your process conditions and ideal performance.
Alicat mainline controllers (MC, PC, LC) are equipped with one or more of the following valve types:
- Small proportional valve: for flow rates of 20 SLPM or less; may be equipped with a custom orifice size (e.g., PCV30)
- Small proportional valve with the largest orifice (P valve): for flow rates up to 250 SLPM
- All-316L high pressure proportional valve (PCA): for use with aggressive gases or pressures above 160 PSIA; may be equipped with a custom orifice
- Large Rolamite valve (R valve): for high-flow applications up to 5000 SLPM; may be specified with a custom hole pattern
- Hammerhead valve (H, PH or RH): pairs two valves together side-by-side to operate as a single valve
Alicat CODA Coriolis controllers and BASIS MEMS thermal controllers all use proportional solenoid valves (same class as PCV valves). The size of the valve is entirely dependent on flow rate.
Factory and user PID tuning
We will tune your flow or pressure controller at our factory to ensure optimal performance for your specific application. If you have given your expected inlet and outlet pressures to an applications engineer, we will use them first to select the right valve and orifice, and then to replicate your expected conditions for valve tuning. If your flow conditions change after installation in the field, you use the Optimize Control option in the SETUP menu to autotune your instrument, or you can manually adjust the PID tuning from the front panel of your device or over a serial connection to your computer.