Pressure Drop?

We have a two year old, 1 1/4" shallow well (outside) system which we use for lawn and garden watering. The system runs approximately 28# pressure when operating normally. There are two Rain-bird sprinkler heads operating off this system which are fed by a 3/4" line from the pump and then reduced down to 1/2" at each head. The system has been operating normally for a time but lately I have noticed a drop in pressure at the sprinkler heads. It appears that the pump is holding pressure around 25-30#. I have cleaned out each sprinkler head to insure no line blockage there. I have not measured the water depth in the well since it was installed but anticipate the water table has remained constant. Additionally, I would not anticipate there would be any rust buildup (so soon) in the well "point".

Question....What might be causing the drop in pressure at the sprinkler heads?

Question....How might I increase the line pressure to around 40-50#?

 

Does this system have a storage tank equiped with a pressure switch to control the pump or do you simply turn the pump on when you want water at the sprinkler heads?

 

There is a pressure switch mounted to the pump (which works)

There is NO pressure tank or storage tank mounted on to the system although I DO have a new one (on the shelf)

 

The only way you can increase the pressure (without a pump repairof some sort) is installing the pressure tank and using a pressure switch to control the pump.

The question now becomes has the pump always had those pressures? How deep is shallow? What is the make/model of the pump? Can you easily pull the foot valve and clean it?

We need to determine whether or not the pump has the capacity to do what you are requiring it to do. Then determine if the well still has the capacity.

 

The pump has maintained the 28-30# pressure for the past two years.

The "redjacket" pump IS (repeat, IS) controlled by a pressure switch.

The well is a "sand point" driven to 42 feet deep (I personally pounded it down). At the time of installation, the top of the water level in the pipe was at 18 feet down. (Should be lots of water down there).

The pump brand and model number are:

 

If the pump pressure remains constant at 25-30 psi with the two sprinklers running, adding a pressure tank isn't going to increase pressure, except, possibly, right after starting. Once the tank expels water, the pressure will level back off at 25-30 psi and stay there. In other words, the well is only supplying enough water to allow the pump to reach 25-30 psi. Cranking up the pressure switch or adding a tank won't help that.
It seems to me that if the pump is still operating where it always did, it should still be delivering the same amount of water at the same pressure. If the sprinklers or piping were plugged up, you would see an increase in the pressure. Is it possible that the nozzles in the sprinklers are wearing out? Perhaps the well produces fine sand, which has eroded the nozzles. Just a thought.
Ron