Reciprocating Compressor Problem

For double acting you compress on the return stroke and you have to seal the piston rod. This is difficult or near impossible if the rod is flexing. This is reason for the crosshead to make the movement stable for the seal. No other reason that I am aware of.

ROY,i am grateful for your short but self explanatory answer couple with the elaboratory answers of the PROF i am more than satisfied,once again thanks alot

Roy is correct in what he says, but there are more reasons for using a crosshead, and yes, some single acting reciprocating compressors use a crosshead design. Some reasons, sure other people will add (or subtract):

• Length of stroke can be greater
• lower side thrusts of the piston to cylinder wall are achieved so nearly all ringless, non-lubricated etc designs use them
• Distance piece can be long for non-lubricated design
• Sealing of crank lube oil from cylinder is possible
• for flammable and or hazardous gases the piston leakage can be sealed at the piston rod packing
• Separate extra distance piece is possible

I feel covered and protected whenever i am in my professional circle,you guys have tremendously for me,the grey area i have has been clear,thanks for been a partner in progress