×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Diaphragm Dosing Pump

Diaphragm Dosing Pump

Diaphragm Dosing Pump

(OP)
Hello,

I have a IWAKI EZ B16D1-VCA diaphragm dosing pump. I have a colleague who is adamant that when this pump is running full speed, 360Hz that if you shut it off fluid keeps flowing and the pump continues to pump. With my experience with a diaphragm dosing pump, as soon as the power is removed from the coil the diaphragm stops moving and the check valves stop the flow.
Has anyone had any experience with these pumps acting like this? I have tried reproducing this condition to no avail.

RE: Diaphragm Dosing Pump

Diaphragm pumps will free-flow in the direction of flow when stopped. If your dosing tank level is above the pump you may experience this. Consider moving the pump above the dosing tank.

RE: Diaphragm Dosing Pump

(OP)
Thank you very much.

RE: Diaphragm Dosing Pump

Agree.

If there is a positive pressure difference between inlet and outlet then flow will continue. The check valves stop the flow going backwards

Also include an actuated valve.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Diaphragm Dosing Pump

(OP)
Please see above, as I did respond to the first reply with a thank you.
And I thank you as well for your knowledge on this situation.
The chemical pump is slightly below the tank, and the outlet is submerged in a tank of moving water. There once was an actuated valve on the outlet but at some point someone decided it was not required and removed it.

RE: Diaphragm Dosing Pump

@Elons, so it sound to me that you source is higher than your destination - then the "pump" will free flow - that is it will stop at once but flow will continue at a lower rate. If your desitation has a higher pressure than your source this may not be the case but thats not clear from the describtion "tank of moving water".

Best regards, Morten

--- Best regards, Morten Andersen

RE: Diaphragm Dosing Pump

Quote (Elons Nephew)

There once was an actuated valve on the outlet but at some point someone decided it was not required and removed it.

Well try and find that person and then make sure you don't listen to them anymore.....

So just replace it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Diaphragm Dosing Pump

Hi,
Make sure your "new actuated valve " will be open at the start of the pump with proper interlocks! Safety concern.
Safety review needed.
Pierre

RE: Diaphragm Dosing Pump

This particular pump is not supposed to siphon:

"Back Pressure / Anti-Siphon Valve
1. A spring-loaded diaphragm under the back pressure knob automatically adds approximately 36PSI (15 PSI
for low pressure versions) of back pressure to the discharge side of the pump when the knob is set to the
“BV” position.
2. The diaphragm also prevents siphoning of chemical through the pump."

If all else fails, read the instruction manual:

Pump Manual

RE: Diaphragm Dosing Pump

That only seems to apply IF it's fitted.

Section 2.5 specifically says it's not an anti syphon valve for the main injection valve.

Section 3.7 where your data comes from is optional and also it needs to be set to BV.

We don't know what is fitted or what position this mysterious multi purpose valve is set at if its fitted.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close