Hi,
I'm working on a reciprocating compressor. I want to calculate unbalanced forces for each throw for foundation evaluation but in the archive we do not have reciprocating and rotating parts weight and specification. can you guide me from where I can get this information?

Try the OEM. If they won't have a dialogue or refuse to give you the info you would need an engineer specializing in that discipline.

A relevant refernce is ACI standard 351.3R-04 “ Foundations for Dynamic Equipment”

Paragraph 3.2.3.3 describes the complexity of the problem of determining foundation loading dynamic forces and moments for reciprocating machines and suggests these should be provided by the compressor OEM (as suggested above). It mentions the OEM may utilize vibration measurements in developing his estimates.

Section 3.7 describes an approach for estimating the loading when OEM data is not available.

ebinadery - nothing directed at you as a person. But, some technology is not reciporal due to governmental constraints.

Your asking this question would seem you have bought someone's surplus equipment. Do you not have support of the OEM? CAn you get that support? Are you willing to pay for help to fulfill your need? Is that help resident? No; then you may want to search within 500 miles and then expand the radius until you find who you need. Just have the info available is not necessarily going to ensure that you have the expertise to install the machine correctly.

A lot to consider. If you're over a ledge and someone tosses lyou a rope, be careful where you tie it or not.

thanks for your help
In fact I'm doing a research and the compressor that I'm working with is a Dresser-Rand built but it's information about weights and phase angles are not available.

I read the ACI standard. It is very useful. Can you help me more how is possible to use vibration to estimate loads. Can you mention some references in this field?

Uh, Dresser certainly has the information. Unfortunately there are issues associated with American companies passing information to people from certain countries (stating with the letter I)....

As an alternative you could weigh the spares. Or you could disassemble your machine and weigh the actual parts....