What a Metering Pump IP65 Rating Really Allows Outdoors
A metering pump IP65 rating is stamped on the motor or the drive housing, often next to IP55. Buyers read metering pump IP65 as "fine to leave outside," then find a wet terminal box and a cover held by two screws. The number on the plate is then meaningless. This note explains what a metering pump IP65 rating actually tests, and how installation either keeps that rating or throws it away.
What the two digits in a metering pump IP65 rating mean
The first digit after IP deals with solids, the second with water. In a metering pump IP65 rating, "6" means a high level of dust protection for live parts, and "5" means the enclosure should stand water jets from any direction. It does not mean the pump can sit in a puddle. Treating a metering pump IP65 rating as a submersible rating is the usual misunderstanding.
These common grades are enough for most chemical-feed jobs:
Figure 1: IWAKI EHN-R solenoid diaphragm metering pump. Image source: IWAKI official website
- IP55: slightly less dust protection, still jet-rated; typical for many motors.
- IP65: better dust sealing and jet protection; often quoted on solenoid pumps and outdoor boxes.
- IP67: a stricter short immersion test, still not continuous submersion.
The laboratory test behind a metering pump IP65 rating assumes the lid gasket and cable glands are in the as-tested condition. Age the gasket or leave a gland loose, and the real protection falls off immediately.
We have seen two pumps of the same model on a cooling-tower site: one lived in a chemical room for years, the other sat on an open platform with the gland facing up. After one rainy season the second board was damp. The model had not changed; the way the enclosure was used had. A pressure washer is also harsher than the lab jet, and water finds the gland threads and the lid joint.
Metering pump IP65 is not a pass to skip shade or a rain roof
Even with a metering pump IP65 rating, the liquid end, the stroke knob, the tubing and any local display still sit in sun and rain. Plastic heads dislike ultraviolet light, and water works into window and knob joints. You still need shade and a rain roof. A metering pump installation diagram does not change outdoors, and the rating does not replace a shelter.
If you need to keep splash off the drive, a protective cover or a simple canopy is more honest than trusting the nameplate. Salt spray and dusty rooms also ask for better seals and coatings; a metering pump IP65 rating alone does not cover those.
Gland direction and lid screws decide whether the rating survives
Most lost protection after a metering pump IP65 rating is an installation issue. Bring the cable in from the side or from below, leave a drip loop, and compress the gland until the seal is actually loaded. A gland pointing up lets rain climb the threads in a few seasons.
Tighten lid screws in a cross pattern and replace a missing gasket section. Two casually tightened screws after a wiring change are enough to turn IP65 into "a lid you can touch." Solenoid pump boxes hold electronics; condensation inside is a common source of odd faults, so open the box now and then and look.
IWAKI EHN solenoid metering pumps are commonly listed with a metering pump IP65 rating and suit a chemical room or a covered outdoor point. Sitting the same unit on an unsheltered roof will defeat the enclosure, rating or not.
How to specify a metering pump IP65 rating on the order
Do not write only "IP65." Describe the site: indoor room, outdoor under a roof, wash-down jets, corrosive gas or dust. The motor, the control box and the pump head may not share one rating; the electronics are usually the weaker part and should be called out separately.
If the floor will be washed with a hose, the jet may exceed the test, so add a cover rather than relying on the plate. Send a photo of the pad if you are unsure, and contact our engineers with the wash-down method and the mounting height. You can also compare series on the solenoid metering pump range and the IWAKI brand page. Brands word the rating slightly differently; use the data sheet and the nameplate for the unit you are buying.
People sometimes put ingress protection next to control options when they compare solenoid pump brands. That is useful background, but you still have to match this pump and this site.
Conclusion
A metering pump IP65 rating means solid dust protection and resistance to water jets. It is not a submersible rating, and it is not permission to leave the pump bare outside. After you read the two digits, point glands down or sideways, tighten the lid, and add shade and a rain roof where the weather requires it. Write the environment and the wash-down method into the order, and the number on the plate will still mean something on site.
FAQ
How is IP65 different from IP55, and can I use an IP55 motor?
The difference is mainly the dust digit. Many mechanical diaphragm pump motors are IP55 and live happily indoors or under a shelter. Keep water out of the terminal box and do not fire a hose straight into the fan cover.
The plate says metering pump IP65. Can I set the pump in a pit?
Pits collect water. Splash for a short time may be tolerable; sitting in a pool is not. Drain the pit and keep the pad above any standing-water line.
What if the control box and the pump have different ratings?
Install to the weaker rating. If the box is lower, keep it out of the spray or give the box its own weather enclosure.
Can I wash the floor by spraying toward the pump?
Even with a metering pump IP65 rating, do not aim a hose at the terminal box, the display or the head seals. Shield the pump during wash-down, or wipe it after you stop the unit.
The nameplate is unreadable. How do I confirm the original rating?
Ask the supplier for that model's data sheet. Do not guess. After a non-original lid, gland or adapter is fitted, the original metering pump IP65 rating may no longer apply; judge the seal as it stands today.