5 replies to this topic

[AliciaN]

Hi Everyone,

 

I was tasked with sizing TSVs for the case of a blocked outlet on plate and fram heat exchangers. But i've heard that the gaskets will blow before the rv lifts so they're unneccesary.

 

I would like to know if they are really neccesary.

 

[fallah]

Hi,

 

If thermal expansion of blocked-in liquid in a P&F heat exchanger would be a credible overpressure scenario, a TSV is strongly necessary to relieve the excess pressure. If the TSV is set at the heat exchanger design pressure it could be opened at the set pressure without gasket blow then you aren't allowed to take any credit on leakage from gasket blow happening to remove the TSV for mentioned scenario...

[ankur2061]

AliciaN,

 

Well blowing of the gaskets for a PHE is obviously not an acceptable criteria. You can still have a TSV for blocked outlet which can be set at a pressure well below the design pressure or the pressure at which the gaskets blow whichever is lower, so that the TSV relieves the overpressure before the pressure accumulates to a value which blows the gaskets.

 

Rupture of gaskets means the PHE needs to be taken out of service and expensive gaskets need to be replaced before the PHE can be taken back in service. In a worst case scenario blowing of gaskets can lead to uncontrollable release and lead to a fire and safety hazard specifically if the released fluid is toxic or flammable.

 

To conclude, having a TSV can prevent the aforementioned scenario.

 

Regards,

Ankur.

[AliciaN]

Thanx for your help.

 

I also want to enquire what the average price of TSVs are generally so I can help defend the reasons for their installation

[fallah]

AlicianN,

 

Considering small size of TSV (typically 3/4" * 1") the price can't be so high to impress yourself to avoid TSV installation for such obvious safety issue...

[breizh]

Alicia N,

 

It's not just a question of $ ! Let you talk to the maintenance guys about replacing gaskets on PHEX .

 

Breizh