Run a high pressure sprayer pump inside its own rated range, set at the bypass while you watch the gauge, and keep it below the working pressure of your hose. On our JP Kissan pumps that range is 20 to 40 bar on the JPK-22, the JPK-50-1 and the JPK-QF-C2 set, and 30 to 50 bar on the JPK-150. Within it, set for the throw the job needs, not for the highest figure the pump can reach.
What does pressure change on a sprayer?
Pressure decides how far the spray throws and how fine the droplet is. Suction, the litres a minute the pump draws, decides how fast you cover the field. They are separate jobs, which is why we size a pump by suction rate rather than by headline pressure. The motor or engine has to match both; if it does not, the pump runs hot and the seals wear early.
What pressure do JP Kissan pumps run at?
| Model | Suction | Rated pressure | Motor | Suited to |
|---|---|---|---|---|
| JPK-22 | 13 to 25 L/min | 20 to 40 bar | 1.5 to 2 HP | Nursery or small plot |
| JPK-QF-C2 complete set | 13 to 22 L/min | 20 to 40 bar | 1.5 to 2 HP | Nursery or small holding |
| JPK-50-1 | 40 to 60 L/min | 20 to 40 bar | 3 to 5 HP | Field spraying |
| JPK-150 | 125 to 170 L/min | 30 to 50 bar | 7 to 9.5 HP | Orchard and plantation duty |
Suction rises several times over from the JPK-22 to the JPK-150, while the pressure range moves by only 10 bar. A bigger pump covers ground faster; it does not need a much higher setting to do it.
Why must the setting stay below the hose rating?
Our agriculture spray hose is rated 50 bar working pressure on the smaller bores and 40 bar at 13 mm, with burst pressure at 120 to 150 bar. Burst pressure is where a hose fails, not a figure to work to. Closing a spray gun sharply also sends a spike down the line that is higher than the gauge shows at the pump, so the hose needs a margin above your setting, not a match to it.
This matters most on the JPK-150. Its range runs to 50 bar, and a 13 mm hose is rated 40 bar, so keep the setting below 40 bar on that bore or ask us which bore to take. Our guide to spray hose pressure rating, diameter and length covers the rest.
How do you set the pressure for a job?
- Check the gauge. It is often the first part to fail, and without it you are setting pressure blind.
- Clean the suction strainer and the nozzle. A partly blocked strainer makes the pump work harder for less output, and a worn nozzle does the same.
- Set it at the bypass, inside the pump's rated range and below the hose's working pressure. The air chamber keeps the delivery steady once it is set.
- Judge the spray at the far end of the run, not beside the pump. Pressure is lost along the hose, more on a narrow bore and a long run.
- For a tall orchard canopy, look at the hose bore as well as the setting. Pressure lost along a narrow hose shows up as a weak spray at the tree top.
What does it mean when the pressure will not hold?
- Will not build, or drops steadily under load: worn piston seals and cups.
- Pulses or hammers instead of holding steady: suction and delivery valves.
- Weeping at the joints: O-rings and gaskets.
Turning the bypass up will not cure any of these. Plungers, ceramic plunger sets, air chambers, filter nets, valves and seal kits for the whole range are on our HTP pump spare parts page, and the full service routine is in our HTP power sprayer maintenance guide.
Which pump should you look at?
Every pump in the series is a three plunger design with its own air chamber, pressure gauge and bypass, supplied as a bare pump or as a complete set on a chassis, tested before dispatch. Compare the range on our high pressure sprayer pump page, then tell us the crop, the acreage and the hose run, and we will size the pump and the hose against them.