O rings compatibility for DEU exchanger

[Muhaka22]

Dear All,

A high pressure ASME Div 2 DEU-type exchanger has silicon o-rings in the channel head cover. We need to evaluate change of service of the exchanger from syn-gas to liquid ammonia (@ same pressure/temperature).

Silicon is not suitable for ammonia service. Can I just replace the silicon o-rings with chemically compatible BUNA/NBR or similar material, without performing any gasket design calculations*?

*Gasket Factor, m for elastomers is 0.5~1.0 as per Table 4.16.1

Thanks in anticipation.

 

[georgeverghese]

Liquid ammonia service will require a lower design temp of -35degC or so, I doubt Buna N / NBR can be used for this.

 

[Muhaka22]

@georgeverghese If we assume that the lower end temperature is not an issue, and that the m-factor of the new o-ring material is same, can the o-ring material be changed without performing any Div-2 gasket design calculations?

 

[georgeverghese]

Am not a PV engineer, so maybe some one else can respond.

 

[kalalsaleem]

Did you ever get the right O-ring?

https://www.canyoncomponents.com/chemical-compatibility-table-o-rings-gaskets-plastics

 

[r6155]

No problem with the factor "m".

Regards