Accumulator (mains booster) vessels - Same nominal volume, huge size difference.

[puntloos]

Both of the below vessels have a nominal volume of 100L (ok, ST is 110, PW is 100). But ST is 558x540x1026, PW is 720x470x470. What am I missing? 

 

(ignore location for now)

 

#1 GWS PressureWave - PWB-100LH (horizontal)

https://www.globalwatersolutions.com/products/pressure-tanks/pump-applications/pressurewave/ - info PDF here: [Data Sheet]

- Pump not mentioned, I assume needs to be supplied separately

- The dimensions are very small for a 100L nominal device, not sure why the Stuart Turner ones are so much bigger

 

#2 Stuart Turner Mainsboost MB-200SH 

https://www.stuart-turner.co.uk/product/mainsboost-mb-200sh-1-22-44747

- As can be seen much larger device, which even sticks beyond the door. Still, 110L nominal so I'm not sure what's going on

- Pump not depicted

[dpmiller]

ummm, the Mainsboost is a 200l vessel?

 

I'm guessing they're just being more conservative about the life of the diaphragm.

 

 

edit: also the *system* has a rating of 3.5bar uplift, so the end volume is variable. The other tank is just talking about it's full capacity I'd think.

Edited July 21, 2023 by dpmiller

[puntloos]

4 minutes ago, dpmiller said:

ummm, the Mainsboost is a 200l vessel?

Mainsboost says 'nominal volume 110L' though, which is the same as the GWS says...

 

4 minutes ago, dpmiller said:

I'm guessing they're just being more conservative about the life of the diaphragm.

edit: also the *system* has a rating of 3.5bar uplift, so the end volume is variable. The other tank is just talking about it's full capacity I'd think.

I am suspecting you are right, "too good to be true" usually is  - but it's still hard to see the real situation. Basically

 

PW: 0.24x0.72 = 0.13 -> 130L volume of the cylinder outer hull

MB: 0.28x1 = 0.28 -> 280L volume of cylinder outer hull

 

So indeed I suspect what one company calls nominal is the other's "maximal" or whatever.