The number one application, is Control valve protection Our 2000 series and 6000 Series filters are designed to protect Digital Valve Positioners . This is handy when Operations is willing to bypass an air dryer or a freeze induces water into your instrument air. The digital valve positioners have much smaller orifices (2 micron) compared to their predecessors and they are more susceptible to moisture and particulate. If a positioner is fouled with water/particulate and it must be repaired, the repair cost can be over $2500 in parts + man hours + whatever other issues an out of service control valve will cost.
This problem can easily be solved by installing a Balston filter directly upstream of the filter/regulator that comes on the control valve.
Balston Features/Benefits:
- Micron filtration rating of 0.01 – it will eliminate all moisture, aerosols and particulate. This provides the cleanest instrument air with the lowest DP in the industry.
- Automatic drain – the operators will not have to open a valve to drain liquids from the filter housing. This filter automatically removes any liquid introduced in the housing. No manual petcock valve required.
- Long Filter Life – The filter tube in this application can last 3-5 years without having to be replaced. When the valve does come out for a turnaround, the tube inside the filter housing can be replaced at a cost of around $20.
Filter/Regulator from Valve mfg.
- Micron rating ( Usually around 40 Microns) – It’s typically a sintered plastic element that acts as a screen. It will remove trash from the line but will not remove water droplet/aerosols
- No automatic float drain – The housings come equipped with a petcock style drain which means the operators will have to physically unscrew the drain to remove any water. Even if the filter removed water, overtime the housing will fill up water and over flow into the valve.
- Filter life – typically, when the valve comes out for a turn around, they will replace the entire valve positioner.
- Old technology - This style of filter/regulator has been around since the early 70’s. They have upgraded the valve positioners but have done nothing to improve the device that protects it.
