Deletion of Discharge Pulsation dampeners

[vjr0512]

For one of the Offshore project, for the API 675, Chemical Injection pumps. vendor has studied the requirement of the Discharge pulsation dampeners and said this is not required. I am giving the reply by the vendor below

Quote

Our process department just finalized the pulsation dampener calculation. This calculation shows that for pumps no pulsation dampeners are required . Proper system operation can be achieved without the use of a pulsation damper if the calculated volume is very small (less than 0.05 liter), the flow is very low (less than 10 l/hr) and the is less than approx. 40 barg. Because all these conditions are met for this damper, it is proposed not to install a damper because proper operation can be achieved without a damper.

Unquote

Thanks to give your views whether the vendor approach of removing the discharge pulsation dampener is correct.?

 

[btrueblood]

Might be true for the pump, but did you calculate the worst case pulsation, and account for that load and number of load cycles (fatigue) in the design/sizing of piping and downstream fittings?

 

[DubMac]

It is a fact of life that reciprocating pumps will have pulsations. It is not a fact that they will be destructive to the process equipment. If a pump has enough pistons/cylinders, the pulsations can be almost undetectable. The difference between a 3 piston pump and a 7 piston pump is astronomical in terms of pulsation signature.
Pulsation dampeners in general are mostly misapplied and ignored. There are some very interesting advances being made in this technology (I witnessed a test yesterday for this) in "real time" pulsation signature matching. Without going too deep into a proprietary prototype; the system reads pressure pulses and creates a "muting" pulse string to offset the pump pulsations. Very cool concept if it can work in the field.

 

[ccfowler]

The pump manufacturer's evaluation is nice to know, but your problem is the whole system. Have you estimated and evaluated your system's performance with and without pulsation dampers? The specific configuration of the pulsation dampers (suction and discharge) will alter their effectiveness. You need to do your own homework to satisfy yourself as to whether or not pulsation dampers are needed. DubMac's comments are most significant with respect to the exact type of pump and system configuration. Since you have provided almost no information on the details of your system, it is impossible to provide much guidance.

Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.