The Hoke HDY Sampling Cylinders are double-ended high-pressure sample cylinders designed for safe collection, transport, storage, and analysis of hazardous gases, liquefied gases, hydrocarbons, and process liquids in analytical and industrial applications. The HDY designation refers to double-ended cylinder configurations with female NPT connections on both ends, allowing installation of valves, rupture discs, bypass systems, outage tubes, or quick-connect sampling assemblies.

The cylinders are manufactured from seamless 316 stainless steel tubing or pipe with increased wall thickness in the threaded areas to prevent expansion during valve installation and high-pressure service. Formed or spun end construction eliminates weld leak paths and maximizes structural strength, while internal sandblasting removes surface imperfections and contamination. Standard pressure ratings are typically 1800 psig (124 bar), with special designs available up to 5000 psig depending on cylinder size and configuration.

Standard capacities range from approximately 10 mL to 1 gallon (3785 cc), with common HDY sizes including 75 cc, 150 cc, 300 cc, and 500 cc versions such as 4HDY75, 4HDY150, 4HDY300, and 4HDY500. Connection sizes vary by cylinder volume and are typically available in 1/8", 1/4", 3/8", and 1/2" FNPT. Optional materials and coatings include Monel, Hastelloy, FEP/PTFE lining, Silcosteel®, Sulfinert®, and PTFE external coatings for corrosive or adsorption-sensitive applications.

Optional accessories include outage tubes, bypass lines, carrying handles, valve protection caps, collars, flanges, rupture discs, and relief valves to improve sampling safety and transport handling. Outage tube configurations are particularly important for liquefied gases to prevent dangerous hydraulic expansion from fully filled cylinders during temperature rise.

Typical applications include refinery hydrocarbon sampling, gas chromatography sample collection, process analyzer systems, LNG and LPG sampling, hydrogen and specialty gas sampling, chemical reaction vessels, surge accumulators, molecular sieve systems, high-pressure laboratory sampling, and process sample transport in petrochemical and semiconductor industries.