QJH Series Globe Valves

1

QJH-10B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Erosion of valve seat by high-velocity steam flow; 2. Corrosion of carbon steel body in humid outdoor environments

1. Control medium flow velocity within 2-3 m/s for steam applications; 2. Apply anti-rust paint to the valve exterior in outdoor installations, inspect quarterly

2

QJH-15B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Wear of stem packing due to frequent opening and closing; 2. Fatigue damage of valve disc from cyclic pressure fluctuations

1. Replace stem packing (flexible graphite) every 1000 opening-closing cycles; 2. Install a pressure stabilizer upstream to reduce cyclic pressure impacts

3

QJH-20B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Clogging of valve cavity by impurities in raw water; 2. Thermal stress damage of valve body during rapid temperature changes

1. Install a Y-type filter (100 mesh) upstream of the valve; 2. Avoid rapid opening of the valve in high-temperature steam systems, preheat gradually

4

QJH-25B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Leakage at flange connection due to improper bolt torque; 2. Wear of valve disc sealing surface by suspended solids in medium

1. Tighten flange bolts according to GB/T 12385-2008 (torque: 25-30 N·m); 2. Regularly clean the valve cavity (every 6 months) in water treatment pipelines

5

QJH-32B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Corrosion of carbon steel components by oxygen in circulating water; 2. Jamming of stem due to scale accumulation

1. Add oxygen scavenger to circulating water system; 2. Flush the valve stem with descaling agent (5% citric acid solution) annually

6

QJH-40B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. High-temperature oxidation of valve body in ＞200℃ environments; 2. Wear of seat sealing ring due to long-term throttling

1. Do not use in environments exceeding 250℃ (rated temperature for Q235B); 2. Inspect seat sealing surface for wear every 8 months, regrind if necessary

7

QJH-50B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Fatigue failure of valve bonnet due to high-pressure operation; 2. Leakage of stem packing under high pressure

1. Operate within rated pressure (≤1.6 MPa) per GB/T 12224-2019; 2. Use double-layer packing structure for high-pressure applications, check packing tightness monthly

8

QJH-65B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Vibration-induced loosening of valve internals; 2. Corrosion of valve bottom due to medium sedimentation

1. Install vibration-damping brackets for valves in pump outlet pipelines; 2. Open the drain plug at the valve bottom quarterly to remove sediment

9

QJH-80B

Valve body/bonnet: Carbon steel (GB/T 699 Q235B); Disc/seat: Carbon steel with stellite hardfacing; Stem: 2Cr13 stainless steel; Gasket: Flexible graphite

1. Erosion of valve throat by high-flow medium; 2. Damage of valve stem due to improper operation (over-tightening)

1. Ensure medium flow rate does not exceed 3 m/s; 2. Use torque wrenches for opening-closing operations, avoid over-tightening (max torque: 45 N·m)

1

QJH-10F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Pitting corrosion of stainless steel in chloride-containing media; 2. Wear of PTFE gasket due to high temperature

1. Control chloride ion content in medium below 200 ppm; 2. Do not use in environments exceeding 150℃ (PTFE's max service temperature)

2

QJH-15F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Crevice corrosion at flange gaskets; 2. Jamming of stem due to chloride-induced stress corrosion cracking

1. Use metal-wound PTFE gaskets to reduce crevices; 2. Avoid long-term static load on the stem, operate the valve at least once a week

3

QJH-20F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Erosion of valve disc by acidic media (pH＜4); 2. Degradation of PTFE gasket by organic solvents

1. Neutralize acidic media (adjust pH to 6-8) before passing through the valve; 2. Verify compatibility of medium with PTFE before use

4

QJH-25F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Wear of seat sealing surface by suspended solids in chemical media; 2. Oxidation of stainless steel in high-oxygen environments

1. Install a 50-mesh filter upstream for media with solids; 2. Use deoxidized media in high-temperature applications

5

QJH-32F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Leakage at stem packing due to thermal expansion; 2. Fatigue of valve body due to cyclic temperature changes

1. Use expansion-compensating packing (graphite + PTFE); 2. Limit temperature change rate to ≤5℃/min

6

QJH-40F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Corrosion of valve internals by sulfur-containing media; 2. Wear of valve disc due to high-pressure throttling

1. Select sulfur-resistant 304L material if medium sulfur content ＞0.05%; 2. Avoid long-term throttling at 10-20% opening, adjust to 30-70% opening

7

QJH-50F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Scaling on valve surface in hard water media; 2. Loosening of valve bolts due to vibration

1. Add water softener to hard water systems; 2. Use lock washers for bolts, check tightness monthly

8

QJH-65F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Cavitation damage of valve seat in high-pressure drop applications; 2. Corrosion of flange surface by marine air

1. Install a cavitation-resistant trim for pressure drop ＞0.5 MPa; 2. Apply anti-corrosion coating to flanges in marine environments

9

QJH-80F

Valve body/bonnet: Stainless steel 304 (ASTM A182 F304); Disc/seat: 304 with stellite hardfacing; Stem: 316 stainless steel; Gasket: PTFE

1. Erosion of valve throat by high-velocity chemical media; 2. Damage of PTFE gasket by excessive flange pressure

1. Control flow velocity below 2 m/s for corrosive media; 2. Tighten flange bolts to specified torque (35-40 N·m) per ASTM F1362

1

QJH-10HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. High-temperature oxidation of alloy components; 2. Creep deformation of valve bonnet at ＞500℃

1. Operate within rated temperature (≤550℃); 2. Conduct annual metallographic inspection of valve body for creep damage

2

QJH-15HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Wear of seat hardfacing layer by high-temperature particles; 2. Leakage of stem packing due to high-temperature volatilization

1. Install a high-temperature dust filter upstream; 2. Use high-temperature-resistant packing (graphite + nickel wire), replace every 8 months

3

QJH-20HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Thermal fatigue of valve body due to frequent temperature cycling; 2. Corrosion of alloy by high-temperature steam with impurities

1. Minimize frequent temperature fluctuations, limit cycling to ＜5 times per day; 2. Use purified high-temperature steam (impurity content ＜10 ppm)

4

QJH-25HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Erosion of valve throat by high-velocity high-temperature gas; 2. Fatigue failure of valve stem at high temperature

1. Control gas flow velocity below 4 m/s; 2. Inspect stem for fatigue cracks annually using ultrasonic testing

5

QJH-32HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Loosening of valve internals due to thermal expansion; 2. Damage of gasket by high-temperature creep

1. Use thermal expansion compensation bolts; 2. Replace spiral wound gaskets every 12 months, even if no leakage is detected

6

QJH-40HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Corrosion of alloy by high-temperature sulfur-containing gas; 2. Wear of disc due to high-pressure high-temperature throttling

1. Use sulfur-resistant GH3039 alloy if sulfur content ＞0.1%; 2. Avoid throttling at ＜20% opening in high-pressure applications

7

QJH-50HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Cavitation damage of seat in high-temperature high-pressure drop systems; 2. Oxidation of valve exterior in high-temperature air

1. Install a cavitation-resistant trim for pressure drop ＞1.0 MPa; 2. Apply high-temperature anti-oxidation coating (Al-Si coating) to the valve exterior

8

QJH-65HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Vibration-induced wear of valve internals; 2. Thermal stress cracking of valve body

1. Install high-temperature vibration dampers; 2. Preheat the valve to 200℃ before introducing high-temperature media to reduce thermal stress

9

QJH-80HL

Valve body/bonnet: High-temperature alloy (GH2132); Disc/seat: GH2132 with stellite 6 hardfacing; Stem: Inconel 718; Gasket: Spiral wound metal with graphite filler

1. Erosion of valve disc by high-temperature ash particles; 2. Damage of stem packing due to high-temperature friction

1. Install an ash separator upstream for flue gas applications; 2. Lubricate the stem with high-temperature molybdenum disulfide grease monthly

1

QJH-10WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Brittle fracture of valve body at ＜-100℃; 2. Frost blockage of valve cavity

1. Ensure material meets low-temperature impact requirements (AKv ≥27 J at -196℃); 2. Install a steam tracing system to prevent frost blockage

2

QJH-15WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Leakage of gasket due to low-temperature shrinkage; 2. Corrosion of alloy by cryogenic media with impurities

1. Use low-temperature-resistant gaskets with shrinkage compensation; 2. Purify cryogenic media to remove impurities (particle size ＜5μm)

3

QJH-20WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Wear of stem packing due to low-temperature brittleness; 2. Fatigue of valve internals due to temperature cycling

1. Use low-temperature flexible graphite packing; 2. Limit temperature cycling (from -196℃ to room temperature) to ＜3 times per week

4

QJH-25WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Loosening of bolts due to low-temperature contraction; 2. Erosion of valve seat by cryogenic fluid flow

1. Use low-temperature alloy bolts (316L) with spring washers; 2. Control cryogenic fluid flow velocity below 1.5 m/s

5

QJH-32WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Brittle fracture of valve stem at low temperature; 2. Damage of gasket by cryogenic fluid penetration

1. Conduct low-temperature impact testing of the stem annually; 2. Use double-gasket structure for LNG applications

6

QJH-40WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Frost accumulation on valve exterior causing structural damage; 2. Wear of disc due to cavitation in cryogenic systems

1. Install thermal insulation layer on the valve exterior; 2. Use cavitation-resistant trim for pressure drop ＞0.3 MPa

7

QJH-50WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Corrosion of valve body by cryogenic carbon dioxide (dry ice formation); 2. Vibration-induced damage of valve internals

1. Keep the valve environment dry to prevent dry ice formation; 2. Install low-temperature vibration dampers in LNG pipeline applications

8

QJH-65WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Leakage at stem packing due to low-temperature friction; 2. Fatigue of valve bonnet due to thermal stress

1. Lubricate the stem with low-temperature grease (perfluoropolyether); 2. Design the pipeline with thermal expansion joints to reduce thermal stress on the valve

9

QJH-80WL

Valve body/bonnet: Low-temperature alloy (0Cr18Ni9Ti); Disc/seat: 0Cr18Ni9Ti with stellite hardfacing; Stem: 316L stainless steel; Gasket: Metal wound with PTFE filler (low-temperature grade)

1. Erosion of valve throat by high-velocity cryogenic gas; 2. Brittle fracture of flange due to improper installation

1. Control cryogenic gas flow velocity below 2 m/s; 2. Avoid applying external force to the flange during installation, use alignment tools

1

QJH-10G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Brittle fracture of cast iron body due to impact; 2. Corrosion of epoxy coating in acidic water

1. Avoid mechanical impact during installation and transportation; 2. Adjust pH of water media to 6.5-8.5 to protect epoxy coating

2

QJH-15G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Wear of rubber gasket due to aging; 2. Clogging of valve cavity by sand and sediment in water

1. Replace NBR gaskets every 12 months; 2. Install a 80-mesh filter upstream in municipal water pipelines

3

QJH-20G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Leakage at stem packing due to loose packing; 2. Corrosion of cast iron in humid environments

1. Tighten stem packing quarterly; 2. Apply anti-rust paint to the valve exterior, especially in outdoor installations

4

QJH-25G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Fatigue damage of valve body due to cyclic pressure; 2. Wear of seat epoxy coating by suspended solids

1. Operate within rated pressure (≤1.0 MPa) per GB/T 12226-2017; 2. Regularly flush the valve cavity (every 6 months) in sediment-containing water systems

5

QJH-32G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Jamming of stem due to scale accumulation; 2. Damage of rubber gasket by high temperature (＞80℃)

1. Flush the stem with descaling agent annually; 2. Do not use in environments exceeding 80℃ (NBR's max service temperature)

6

QJH-40G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Loosening of valve bolts due to vibration; 2. Erosion of valve throat by high-velocity water flow

1. Use lock washers for bolts, check tightness monthly; 2. Control water flow velocity below 2.5 m/s

7

QJH-50G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Brittle fracture of cast iron flange due to over-tightening; 2. Corrosion of valve bottom due to sedimentation

1. Tighten flange bolts to specified torque (20-25 N·m); 2. Open the drain plug at the valve bottom quarterly to remove sediment

8

QJH-65G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Wear of valve disc due to long-term throttling; 2. Aging of stem packing in dry air environments

1. Avoid long-term throttling at ＜30% opening; 2. Lubricate the stem packing with silicone grease every 8 months in dry environments

9

QJH-80G

Valve body/bonnet: Cast iron (HT200); Disc/seat: Cast iron with epoxy coating; Stem: 2Cr13 stainless steel; Gasket: Rubber (NBR)

1. Leakage at valve body seams due to casting defects; 2. Damage of rubber gasket by oil contamination in water

1. Conduct pressure testing before installation (per GB/T 13927-2008); 2. Remove oil contaminants from water media before passing through the valve

How to select the correct suffix (B/F/HL/WL/G) for QJH series globe valves according to the application environment?

Select B suffix (carbon steel) for general non-corrosive media (water, oil) in industrial pipelines; F suffix (304 stainless steel) for corrosive media (acid, alkali, salt) in chemical or marine environments; HL suffix (high-temperature alloy) for high-temperature media (＞300℃) such as steam, flue gas in power plants or petrochemical units; WL suffix (low-temperature alloy) for cryogenic media (＜-40℃) such as LNG, liquid nitrogen; G suffix (cast iron) for low-pressure non-corrosive media (municipal water, air) to save cost.

What are the key maintenance points for QJH series globe valves in long-term operation?

1. Regularly inspect sealing components (gaskets, packing) for wear and replace them according to the environment (3-12 months); 2. Clean the valve cavity and internals periodically to remove sediment and impurities; 3. Conduct pressure testing annually to check for leakage; 4. Lubricate the stem and moving parts with appropriate grease (high-temperature/low-temperature/corrosion-resistant type according to the environment); 5. Avoid over-tightening or violent operation during opening and closing to prevent damage to the stem and disc.

What is the maximum operating pressure and temperature range for QJH series globe valves of different suffixes?

B suffix (carbon steel): Max pressure ≤1.6 MPa, temperature -20℃ to 250℃; F suffix (304 stainless steel): Max pressure ≤1.6 MPa, temperature -196℃ to 150℃; HL suffix (high-temperature alloy): Max pressure ≤2.5 MPa, temperature -20℃ to 550℃; WL suffix (low-temperature alloy): Max pressure ≤1.6 MPa, temperature -196℃ to 80℃; G suffix (cast iron): Max pressure ≤1.0 MPa, temperature -20℃ to 80℃. Specific values should be confirmed with the product datasheet for special applications.