viscosity

A Newtonian fluid has a constant number for its viscosity while a non-Newtonian fluid has viscosity that changes with the velocity gradient applied to it.

Both glycerol or glycerin and soap are non-Newtonian: Very often the fluids with complex molecular structures, as are glycerin and soap, are non-Newtonian.

I think there are viscosity meters, just google it - just checked and found one on Globalspec.com

we have glycerine of 1.285 specific gravity

can u please tell me how much will be the viscosity approximately.

It's not possible. It depends upon temperature, for one thing, which isn't stated here.

By viscometer, device for measuring viscosity; commonly in the form of a calibrated capillary tube through which a liquid is allowed to pass at a controlled temperature in a specified time period.

Also, see Wikipedia, the free encyclopedia: Today, a rheometer is a laboratory device used to measure the way in which a liquid, suspension or slurry flows in response to applied forces. It is used for those fluids which cannot be defined by a single value of viscosity and therefore require more parameters to be set and measured than is the case for a viscometer. It measures the rheology of the fluid.

There are two distinctively different types of rheometers depending on the geometry of applied stress. Rheometers that deal with shear stress are called shear rheometers, whereas rheometers that apply extensional stress are extensional rheometers.

Non-newtonian fluids are those that have viscosity dependent on shear rate. Shear rate measures how quickly the fluid is being poured (or deformed, it it's too thick to pour.)

Rheoplectic - visconsity increases with shear rate. Think silly putty. Leave it alone, it flows, hit it with a hammer, it shatters.

Thixotropic - viscosity decreases with shear rate. Think ketchup. Turn the bottle upside down, it stay there. Shake it, it quickly pours out.

what about soap

is it rheoplectic or thixotropic?

I'm an engineer, not a chemist, but I believe soap is thixotropic, based on the fact that soap and oil together make grease and grease is thixotropic.

actually i want suggestion from engineer

if soap is thixotropic which viscosity increase with shear rate

and centrifugal pump is high shear pump is it adviceable to use centrifugal pump for pumping soap

we are using both centrifugal high shear pump and lobe pump low shear pump

but the line leakage of lobe pump is too much

what will be the reason

how can i solve this problem

now i m trying expansion joint

I would not use a centrifugal pump for soap. The pump may be high shear, but the piping would not be. You'd probably end up with a layer of soap on the OD of the pump and an empty space inside. Use a positive displacement pump.

I'm just a little bit out of my normal field here. Anyone with additional input?

Can you contact the soap manufacturer? Or maybe another soap manufacturer?

Diaphram (if chemically compatible) or piston sound best to me.

i have lobe pump to transfer soap

but the problem we have knoking vibration in transfer pipe line how can i eliminate

As said, this is a little out of my normal experience but, since no one else is here, I'll do my best.

How thick is the soap? Are we looking at shampoo, or material to be cast into bars of soap?

There is a good chance you're getting cavitation. The soap is thick enough that it doesn't completely fill the space left by the lobe. The next lobe collapses that void causing a "water hammer" effect. You might try increasing the pressure at the pump inlet, maybe by lowering the pump or raising the reservoir, and/or slowing the pump to give more fill time.