Non-Recirculating Vessel Sampler
These vessel mounted sampling systems extract a sample from a vessel through a dip pipe mounted on the lid and capture this in a sight glass, from there it is dispensed into the sample bottle. The sample is either forced up the dip pipe into the sight glass with pressure if the vessel is pressurised, or if it is working at atmospheric pressure or under slight vacuum then vacuum is used to draw the sample from the vessel.
Each vessel sampler is designed to suit the customer’s requirements with nearly no two being quite the same. Materials of construction can be stainless steel or PFA / PTFE lined for sampling high corrosive media.
The sampler has a manifold mounted at the top of the sight glass section, to this service valves are connected, these control the vacuum or vent to draw the sample into the sight glass, a compressed gas which is usually nitrogen to purge the sight glass clear and blow the dip pipe clear into the vessel and sometimes a connection to a wash liquor like a solvent to clean the system of any residue. We can also include another port for a pressure gauge or just for future use.
Valves can be as per customer site requirements and we would use the Atomac range of valves for PFA lined sampling systems as they are robust and offer long service life.
The sight glass section is constructed from robust 9mm wall borosilicate glass tube with an outer acrylic safety shield. The sight glass section contains a hollow PTFE ball which floats on the sample liquid and sits on a castellated PTFE seat. At the top of the sight glass section there is a Chemraz FFKM soft seat which seals against the floating ball and prevents any sample liquor being drawn into the vacuum line. There is a wide range of capacity options to suit the sample volume that the customer requires. Where there is a risk of solvents attacking the acrylic shield, this can be replaced with a FEP shield.
Below the sight glass section we have a dispensing arrangement which can be another valve to release the sample from the sight glass section into the sample bottle, or we would recommend that a SD IL 400 inline sampler is used as it has no product hold up areas, with a spring loaded safety handle and lockable design.
This lower dispensing manifold is bolted to a vessel isolation valve which is connected usually with a reducing flange to the dip pipe process flange. Along with any sampler we would be happy to supply a fully PTFE lined dip pipe.
The maximum operating temperature is limited to 180° and the maximum working pressure is 10 barg.
Special designs can be produced, for instance with bulls eye sight glasses and Belleville washers for cryogenic services, high temperature applications and so on. We can incorporate eductors to produce the vacuum required using a compressed gas source if site vacuum is not available.
As with all our samplers and sampling systems we would recommend that the sample bottle is contained within safety cabinet, this protects the bottle, operator and environment. Our standard cabinet is stainless steel with a laminated glass door.
To help specify a sampling system we have a questionnaire which you can download.