Question about air locking the spa's main suction line.

[Mark McLeroy]

I have an automatic valve actuator controlling a valve that diverts suction water from the pool to the spa. When I close the pool for the season, I need to airlock the spa's main suction line. With a manual valve I can close it quickly to air lock it. But since this valve has a electronic actuator, the movement of the valve is very slow. I can continue to blow air into the line as the valve is actuating, but as the opening get smaller will the airflow be enough to keep the water out of the line until the valve is completely closed? Keep in mind, I have a cyclone blower for the job.

Thanks,
Mark McLeroy

 

[Rancho Cost-a-Lotta]

Hi Mark. Why not just bypass the actuator and use the valve in manual mode? If I recall, you loosen the nut on top of the handle without removing it, and then pull the handle up until it will turn manually. This way you could close it faster and not wait for the actuator to do its work.

 

[Newdude]

Either way, it's like blowing through a straw at full force and pinching the straw. The resting water pressure will not be able to overcome whatever air is still going through the straw, whether you pinch the straw quickly or slowly.