I may be very late to comment but still I would recommend anyone to approach CCI valve (Control Components Inc. California Tel : 01-949-858-1877) for a guaranteed trouble free operation. visit : ccivalve.com
For more information on Control Valves, problems & solutions visit "ccivalve.com" ( contact - Control Components Inc.California, Tel 001-949-858-1877.)
Consult CCI valves - control components Inc. - California -001-949-858-1877 - visit ccivalve.com.
They make sampling (analyser)valves which can be used even at inlet pressures 6000 psi (approx.400bar)and downstream pressure as low as atmosperic.