Summarized questions from customers.

1. Self-priming pumps 　　2. End suction pump 　　3. Submersible pump 　　4. Centrifugal sealless pumps
5. General FAQ 　　6. Oil collecting systems

Is a foot valve required on the suction side?

No. (But this applies only for the suction lift pump as described in the catalogue.) Our self-priming pump has a mechanism that retains a sufficient amount of priming water for the next run once the priming water has been filled. If you use a foot valve with surfactant mixed liquid that generates a large amount of foam, it may cause the self-priming operation to malfunction by blocking the air outflow when the self-primer started.

What are the precautions when installing or removing the pump?

First, please read the safety precautions in the instruction manual before proceeding with the installation or removal. For installation, please be sure to take out the “Protection Seal” on the suction/discharge openings. For removal, please turn off the main power first. Then, disconnect cables and close the piping valve on inflow/outflow side. Remove liquid through the drain cock and dismount the pump. Please be careful not to splash liquid.

I ran the pump without filling up the priming water first. I soon realized and turned off the pump. Was I able to avoid the damage? Does the pump work OK?

The pump may be damaged from dry running. Please contact the distributor and obtain more information by providing the pump type and product serial number.

I turned on the pump, but pumping doesn’t start. There is a sufficient amount of liquid on the suction side, and the pipe diameter is in the proper size. I checked the rotating direction and didn’t recognize any error. What would be the reason why pumping doesn’t start?

Among several possible reasons, the pump may have some air trapped inside. If the air removal system is installed on the discharge pipe, please use the system to remove the air and fill priming water in the casing. Or by repeatedly turning the pump ON and OFF (start and stop) a few times, it may move the air so that priming water fills in the casing. If no air removal system is installed but the check valve is installed on the discharge pipe, please install the air removal system between the check valve and casing discharge opening. And when switching pumps, please be sure to remove the air and check if priming water is filled before operating the pump.

Some foreign substances may have been stuck and the pump is making abnormal noise. Will removing the foreign substances clear the noise?

Even though you remove the foreign substances, they may have damaged inside of the pump by abrasion. Please contact the distributor and report the problem.

Can I use the submersible pump for highly concentrated strong acids and/or alkaline liquids?

The submersible pump cannot be used for certain kinds of liquids. Please contact the distributor to verify what kind of liquid the pump can be used for by providing the liquids information (name of the liquid, concentration, specific gravity, temperature, etc.).

Is there a submersible pump with single-phase 100V specification?

No. We only offer a single specification with 3-phase 200V, 1.1kW motor.

I’d like to replace some parts. Are disassembly and reassembly quite simple?

They will require several complicated procedures, such as: centering the unit and adjusting the impeller clearance. We recommend the parts replacement done by our technicians or your local distributor.

The pump has a heavy vibration and the discharge volume seems much less than it should be. What are the possible reasons?

Cavitation may have occurred because the pump cannot maintain adequate liquid inflows through the suction pipe. Please check the following to remove the possible causes: if crystal or other substances are stuck in the suction pipe, if the strainer is installed and clogged with crystals or other substances and lastly if there is any air entrapped by the occurrence of vortex flow which would be caused by low liquid level on the suction side.

Liquid leakage occurs to the NSF-type pump when it is turned off？

Temporary liquid leakage may be occurred by a large amount of residual water at the time of shutdown. NSF has a mechanism that keeps some priming water (residual water) for the next run when it stops. When the flow speed of backwater from the discharge pipe to inside of the pump is faster than the one from inside of the pump to the pit, temporary liquid leakage may occur to the lower part of the pump because some of the backwater cannot go anywhere but flows into the upper part of the pump. In addition, temporary liquid leakage may also occur when the foot valve is installed: the valve blocks the backwater moving from inside of the pump to the pit, and more than acceptable amount of liquid inside of the pump flows back through the discharge pipe.

When the NSF-type pump was first installed, no liquid leakage occurred. But recently, the liquid started leaking. Why is this happening？

It may be happening because the seal effect is worn out as the rubber’s elasticity for the seal has weakened, causing inflexibility. Or possibly, the liquid leakage may be caused by the reasons described previously above. The NSF is equipped with a dry seal that seals gas and prevents motor corrosion that is potentially harmed by liquid gases. The dry seal has a high seal ability to prevent rising gas or external leakage of gas, but not to seal any liquids. When the pump is first installed, the dry seal has some rubber elasticity and may be effective to seal liquids. However, as the rubber’s elasticity becomes weakened by chemical attack or age deterioration, the dry seal can no longer seal liquid. * The main function of the dry seal is to seal gasses, not liquids. If liquid pressure is generated, please use the NSF-type pump with built-in linear seal. Or for self-priming and end suction pumps, please select the GV-type model (Horizontal self-priming magnetic pump).

Do you offer any product lineups connected with thread type or union type other than flanges type?

Yes, several types of our pumps such as our small-size magnetic pumps have a few lineups. Please contact the distributor for more information.

Are pumps equipped with dry running prevention mechanism?

No, our pumps are not equipped with a dry running prevention mechanism. We offer a “dry running prevention system” that detects abnormal current value and forcibly disconnects the electrical circuit related to the pump activation. This system is sold separately, so please contact your distributor for more information.

What is the maximum liquid temperature the pumps can resist?

Each pump has different upper temperature limits. The corrosion resistance of a pump varies depending on the relationship between the chemical concentration and temperature. So please contact your distributor and obtain more information by providing your pump type and application use.

Is the corrosion resistance chart available?

Yes, however, the main purpose of the corrosion resistance chart is to provide a reference to selecting the proper pump. The chart shows corrosion resistance of pumps under restricted conditions and is subjected to change by each application.

Can you quote liquid requirements/conditions by PH value?

No, we will need more information besides the PH value. Corrosion resistance on connection parts varies depending on: liquid type, concentration and temperature. Even though different liquid types have the same PH value, they may not be able to use the same resin. When you inquire for a quotation, please provide information on: liquid type, temperature and specific gravity in addition to the PH value.

Can oil be collected from emulsioned liquid (turbid liquid, mixture of water and oil) using the system?

Oil collecting system and separator operates using the difference in the specific gravity of water and oil. The system can transfer emulsioned liquid; however, it cannot separate oil from emulsioned liquid in the same amount of time of our separators on a standard basis.

The system does not seem to be separating much oil as it is supposed to be. What are possible causes?

It could be caused by various reasons depending on the situation. Please contact your distributor and provide detailed information on the situation because it will often be very helpful to determine the cause.

Can the system collect foreign substances or waste other than oil?

It could be caused by various reasons depending on the situation. Please contact your distributor and provide detailed information on the situation because it will often be very helpful to determine the cause.

How much can the system separate oil and water?

It could be caused by various reasons depending on the situation. Please contact your distributor and provide detailed information on the situation because it will often be very helpful to determine the cause.

What are the differences between GYROSYSTEM and GREASECOMING?

Examples of use for GREASECOMING: The suction pump is installed on land and assembled with a positive displacement self-priming pump (Such as: Moyno type, vayne type or monoflex type). It can be used for various types of floating substances such as: oil with relatively high viscosity (food oil, ect.), mineral oil, or scum.

In regard to the corrosion resistance of GYROSKIMMER, can it be placed in acid or alkaline liquid?

No, it cannot be placed in acid or alkaline liquid. The submersible pump, frame or other parts installed on GYROSKIMMER is not resistant to neither acid nor alkaline liquid.

What is the upper temperature limit of this system?

The maximum temperature for standard type of GYROSKIMMER and GREASECOMING is 40. The minimum is the temperature range before floating oil becomes solidified. Washing saver can be used repeatedly until it reaches the maximum of 95. Please contact the seller for detailed information.

What are the reasons why the collecting system has lower collection flow rate compare to other companies’ systems?

It is because our system has a higher collecting efficiency. Collection flow rate and collection rate are not the same. Collecting only the thin layer of floating oil will deliver higher collecting efficiency as it floats in a thin surfaced layer. On the other hand, collecting from a thickly layered surface will cause higher ratios of fluid to be collected, thus lowering the collection rate. The patented double float technology from World Chemical collects wide-spread floating oil on thin surface layers. Other companies’ systems have a higher collecting rate but only because they collect from a thick layer. They are not able to collect from a thin surface layer since their collection will be diluted with excess liquid such as water.