# What kind of pressure switch can I use for pressures up to 5-10 tons/cm^2?

I need a pressure switch for an electric circuit that has to be closed once a piston is compressing at a pressure of (approximately as we haven't specified how much force we have to use, and maybe it will be greater) 5 tons/cm^2 (75000 psi). The problem is that I can't find any model that satisfies these characteristics due to either

1. them not being as common as to be talked about in the sites I can access
2. my abilities at intelligent Google search are not good enough or
3. them not existing.

I can't believe a component like that doesn't exist and I'm very confident about my intelligent Google search skills so, can someone tell me if there's a chance I can get to know about components like that?

I would be very thankful if anyone could give me a model or a brand or any reference or recommendation to find such information (or about why I won't).

• Use a pressure reducer to restrict the range you measure - but take care with accuracy. – Solar Mike Jul 5 '18 at 20:48
• @SolarMike Thank you very much for your idea, but I fall in the same problem. The toughest pressure reducing valves I find are for a maximum of 5000 psi and that's way below the pressure I'd be using. – c3r38r170 Jul 7 '18 at 2:24

You do this by monitoring the hydraulic pressure rather than the press tonnage.

Since force = pressure x area we can rearrange so that pressure = force / area.

• Using your quaint units of measure, 5 ton = 5 x 2,240 lbs* = 11,200 lbs.
• Let's say your hydraulic cylinder has a cross-sectional area of 2 sq. in. then pressure = 11,200 / 2 = 5,600 psi.

In that case you would be looking for a pressure switch that can be set to 5,600 psi. You would tee this into the drive line of your press.

Figure 1. An image search for 'digital hydraulic pressure switch' throws up an impressive array of options.

• 1 imperial ton = 2,240 lbs.
• Thanks but I'm afraid (and really sorry) I put the information wrong, its already pressure just that it is 5 tons/square centimeter (more than 75000 psi). Thank you very much for your answer and I'm really embarrassed about my mistake! – c3r38r170 Jul 6 '18 at 23:38

Let me just start by saying... what an awful unit of measure. Tons/cm^2?? Whew... that's gut wrenching.

Anyways, this range of pressure transducer certainly exists, albeit they are expensive. These are easiest to find by using the keywords "ultra high pressure transducer". Here is an example --> Click me!

• Welcome on the Engineering SE! Note, posts not looking advertising are much more welcomed. – peterh Aug 11 '18 at 0:48
• Whoops -- just realized I misread the original post. Thought it was asking for a ducer instead of a pressure switch. My bad. – Austin Prater Aug 11 '18 at 1:01