Several options are available for your grab sampling system, such as additional instrumentation - gauges, flowmeters, and transducers; sample coolers—sentry sample coolers; process connections—threaded and flanged connections; enclosures and stands; automation—add a pneumatically or electrically actuated valve to automate your sampling sequence; and exotic alloys—certain components are available in alloy 400, alloy C-276, or alloy 600.
Outage tubes provide a vapor space of the desired volume in cylinders containing liquefied gases, so that liquid in the cylinder can expand if the temperature increases. Without enough vapor space, a small temperature increase can cause the liquid to expand and increase the pressure dramatically. Outage tubes are welded to the male inlet end of an adapter or tee. This adapter or tee is then threaded into the female port of a sample cylinder. The tubes can also be welded directly to the male inlet of a Swagelok non-rotating stem needle valve. The valve is then threaded into the female port of a sample cylinder.
Needle valves have a preferential shutoff direction for restraining pressure and the valve will be oriented such that it is best situated for resisting the internal pressure of the cylinder. The D Series is widely used due to its replaceable stem tip and compact handle.
Swagelok rupture disc units protect sample cylinders from over pressurization by venting the cylinder contents to atmosphere. The use of a rupture disc is recommended with chemicals that may rapidly expand and pressurize due to temperature changes.
The rupture disc is welded to a body that is threaded into a valve body or a rupture disc tee and sealed by an elastomer O-ring. The rupture disc can be easily replaced without removing the valve or the tee from the cylinder.
The carrying handle is an optional purchase that provides a convenient and safe way to carry sample cylinders. The handle is constructed of 304 stainless steel and is available for use on 300 cm3 and larger cylinders.