Rising Stem GOST Certified Industrial Globe Valve for Steam

Featuring an outside screw and yoke (OS&Y) architecture, Hanno's Rising Stem GOST Certified Industrial Globe Valve for Steam keeps actuation threads outside the process flow path to eliminate lubrication wash-out. Engineered with a 2Cr13 stainless stem, 13Cr overlay seats, and die-formed flexible graphite packing, the valve disc retracts completely out of the high-velocity steam path to minimize mechanical seat erosion.

High-Temperature Steam Trim Protection

High-pressure saturated and superheated steam service exposes internal valve components to severe thermal shocks, wire-drawing erosion, and rapid seat galling. Hanno Valve Rising Stem GOST Certified Industrial Globe Valve for Steam overcomes these aggressive operating conditions through targeted thermal metallurgy and optimized structural mechanics:

• Anti-Galling Hardfaced Trim Metallurgy: High-velocity steam flashing causes deep wire-drawing grooves across standard carbon steel seating surfaces. Hanno applies a dense plasma-arc welded 13Cr stainless steel overlay onto the 25L body seat and A105 forged disc. This hardfacing maintains a minimum surface hardness of 350 HB at elevated temperatures, resisting microscopic particulate impact and steam cavitation.

• External Thread Protection via OS&Y Architecture: In non-rising stem valves, high-temperature steam strips thread lubricants and causes severe corrosion on stem drive threads. Hanno's OS&Y rising stem design keeps the stem threads entirely isolated above the packing gland. The stem translates smooth linear motion through an aluminum-bronze or high-tensile brass stem nut (Part #16) supported by heavy-duty GCr15 ball bearings (Part #15), dropping handwheel operating torque significantly.

• Thermal Shock Resistant Bonnet Sealing: Thermal cycling in boiler feed lines causes differential expansion between the body flange and bonnet studs. Hanno utilizes high-tensile ASTM A193 Grade B7 alloy studs and A194 Grade 2H heavy hex nuts to clamp a 304+flexible graphite spiral wound gasket inside a fully enclosed spigot groove, maintaining elastic gasket recovery during rapid steam startups and shutdowns.

Complete Specifications

Steam Utility Application Scenarios

• District Thermal Heating Mains: Main steam header cutoff, pressure reduction bypass loops, and municipal boiler isolation manifolds (China Huadian Group projects).

• Chemical Processing Utilities: High-temperature saturated steam supply lines for jacketed reactors, reboilers, and heat exchanger stations.

• Petrochemical Refinery Utilities: Steam stripping lines, boiler blowdown manifolds, and superheated steam distribution loops (Rosneft suppliers).

Frequently Asked Questions (FAQ)

Why is an OS&Y rising stem structure superior to a non-rising stem for steam pipelines?

The Rising Stem GOST Certified Industrial Globe Valve for Steam design keeps drive threads out of the hot, moist steam medium to prevent lubrication failure. Additionally, the rising stem gives plant operators an immediate, clear visual check of the exact valve opening position.

How does Hanno prevent gland packing leakage during extreme temperature cycling?

We install die-formed high-purity flexible graphite rings compressed by a two-piece self-aligning gland flange (Part #11). This configuration distributes packing pressure uniformly without cocking or stem scoring.

What material documentation comes with steam-rated GOST valves?

Every shipment is accompanied by EN 10204 3.1 Material Test Certificates detailing heat numbers, chemical composition, tensile strength, and 100% hydrostatic test results.