Piston suction pump versus external gear pump as vacuum pump

[johnthekid]

What do you think? Have you thought about the pressures on each side? And have you thought about how it will be built to withstand those pressures and what it takes to seal the joints?

We will need to weld any openings if the container is a steel container. Is there a shape that is more appropriate than cube?

 

[Averagesupernova]

I'll ask it again:

Have you thought about the pressures on each side?

 

[jrmichler]

The best vacuum pump depends on your needs. You need to specify two things - the amount of vacuum and the flow rate before we can give you useful advice.

Amount of vacuum could be, for example: 1 inch of water, 20 inches of mercury, 10 torr, 1 torr, 1 millitorr, or other. You need to specify the amount, and know why you want that much vacuum. You need to know how much vacuum you need because higher vacuums cost more.

Flow rate: When evacuating a vessel, this could be as simple as specifying that you want to reach that vacuum in 1 second, 1 minute, 1 hour, or 1 day. You need to specify the volume subject to the vacuum, and the time to get to that vacuum. You need know what flow rate you need because higher flow rates cost more.

We need real numbers to help you with your vacuum pump. And real numbers to help you with your vacuum vessel.

 

[Averagesupernova]

If you are just comparing pumps to see which can achieve the highest vacuum I don't see why you even need a vacuum vessel. A hose with a gauge on the end will suffice. This whole thing stinks of you trying to hide what you are doing. Now the question is what is it that you are really doing that is against forum rules so you need to hide it? Or are you simply that uninformed so you do not realize what you do and do not need for this?

 

[Baluncore]

Even if both are designed as simple as possible? Now I'm curious about the Torr range that a piston pump with pressure operated check valves and an external gear pump can produce.

The piston pump valve requires a pressure difference to lift it. That pressure drop reduces the depth of the vacuum that can be pulled.

Vane and gear pumps do not have valves. The ports open and close based on the position of the vane, or the gear tooth.