I made a thing

[therecklessengineer]

Anyone care to guess what it might be?

[nigelb]

I'm going guess it's a thing to measure pressure

[Julian]

Tempted to say venturi/ejector looking at the vac/press gauge, but I rather suspect knowing you it'll be a bit more than that.

[therecklessengineer]

10 points to Julian.

It's a proper hairy chested ejector machined from finest scrap stainless. It's actually mark 2. Mark 1 used all the same parts but the nozzle distance from the throat was too great. That and I sealed it with o rings... Which leaked. Now it's fully welded.

I propose a competition. Who'd like to bet on the vacuum generated when attached to a twin stage pump?

[Tony]

29" mercury

[Julian]

I can pull 25 - 26" Hg (depending on fluid) with Franken pump and a four port venturi whose throat size I've long forgotten.

29" is one heck of a vacuum ... I think 29.9" is perfect, and I believe quite difficult to obtain, so I'll go with 27" Hg.

What's the prize?   All I've got so far is points!

[kamaangir]

7 Torr!

[nigelb]

I'm pretty sure I pull close to 30" with my venturi and pump.

I thought that was a pressure gauge in your piccie James...bit tricky to tell with my eyes.

[therecklessengineer]

Well, in it's previous form it would do -0.8 Bar - eventually and as soon as there was any flow into the vacuum port it would drop right off. I'm hoping it'll pull the same vacuum and shift more fluid.

Really, I'm just pleased I managed to stick it together while the ship was rolling.

[Rotary-Motion]

is that a double gauge? needle goes up for pressure and down for vacuum? just needle isn't set at bottom of scale

[Head Womble]

is that a double gauge? needle goes up for pressure and down for vacuum? just needle isn't set at bottom of scale

Yep, goes from -30 to +100.

[nigelb]

A bit like this one....didn't know you could get such a thing:

http://www.ebay.co.uk/itm/Compound-pressure-vacuum-gauge-1-4-Bar-PSI-100mm-1-2-BSP-slurry-tankers-etc-/130902901526?pt=UK_BOI_FarmingEquipment_RL&hash=item1e7a6bc316

[knighty]

A bit like this one....didn't know you could get such a thing:

http://www.ebay.co.uk/itm/Compound-pressure-vacuum-gauge-1-4-Bar-PSI-100mm-1-2-BSP-slurry-tankers-etc-/130902901526?pt=UK_BOI_FarmingEquipment_RL&hash=item1e7a6bc316

I've never seen one before either... never really thought about it but if I needed something like that I'd have probably assumed they exist...

but now that you've ebay linked to one.... I need to fine a use for one so I can buy one :-o

[Julian]

A pure vacuum gauge is probably of more use on a venturi as it gives a larger scale.

Typically ...




http://www.ebay.co.uk/itm/Vacuum-Gauge-New-50mm-1-0-Bar-30-Hg-1-4-BSPT-Bottom-connection-/130889607929?pt=LH_DefaultDomain_3&hash=item1e79a0eaf9#ht_563wt_861

A mere £4.25

[therecklessengineer]

Yes, a pure vacuum gauge would be better. The one above is one that was floating around the ship, so I borrowed it. I've got a pure vacuum gauge at home that will go on.

Normally in industry, every pump has a pressure gauge on the suction and discharge lines. The suction gauge should be able to measure vacuum as well as pressure. That's the purpose that the one above was designed for -  pump suction side pressure reading.