Blog 01: Sample cylinders - Temperature limitations
Sample cylinders
The possibilities for selecting spun end sample cylinders are limited in materials.
Most known fabricates are Swagelok, Parker, Hoke and Fitok.
These suppliers delivers SS-304L, SS-316L or Monel, not all can deliver conform NACE compliant. All suppliers can deliver NACE on the Monel cylinders but Fitok for example delivers SS-316L with NACE.
For additional corrosion resistance the Stainless Steel cylinders can be PTFE lined internal, be treaded with Sulfinert (SilcoNert) coating or with Ceramic coat.
The typical “piston type” cylinders can be made of Titanium but are a lot more expensive.
TPED or DOT = Europe or US (or other non-Europe countries)
TPED = Transportable Pressure Equipment Directive
The Transportable Pressure Equipment Directive (TPED) provides requirements relating to the design, manufacture, and testing of transportable pressure vessels and accessories, including sample cylinders and cylinder valves, used in gas service. The intent of the directive is to provide a uniform level of product safety throughout the countries of the European Union.
Fitok sample cylinders and cylinder valves comply with directive 99/36/EC (TPED) as established by a Notified Body and include an EC-type examination.
DOT = U.S. Department of Transportation
The United States Department of Transportation (D.O.T.) is a department of the U.S. Federal Government which oversees all issues regarding transportation within the United States of America and U.S. Territories.
Its influence around the world is great and widely respected, but its jurisdiction and power of enforcement is limited to the USA and its territories.
Pay attention to temperature limitations!
We are here talking about high pressure high alloys steel materials used for these kind of sample cylinder but pay attention to the fact that the TPED and DOT pressure limitations are related to the operating temperature.
The maximum pressure rating is only suitable at 37 °C for DOT cylinders and conform the brochures the TPED cylinders are limited to an operating temperature of 50 °C maximum!
Andre van Roon (Certified Industrial Sampling Systems Engineer)
08-04-2019 21:17
