Class 1500 LB Gate Valve Packing, API 622, Graphite, 68*88 mm

Product Name: Low-Emission Packing Set for Class 1500 LB API 6D Gate Valve
Model: M600
Size: ID 68 mm * OD 88 mm * 6 Rings
Material Properties:
Graphite Purity: ≥99%
Metal Wire Content: 20% (Inconel 600)
Sulfur Content: ≤50 PPM
Chlorine Content: ≤20 PPM
Operating Conditions: –45 °C to +425 °C 
Certifications:
ISO 15848-1 (up to 400 °C)
TA-Luft
API 622 (incl. 400 °C fire-safe)

Operating Parameters

Speed: 2 m/s
Temperature Range: -200°C to +400°C (for most media), -200°C to +550°C (for steam)
pH Value: 0 to 14
Pressure: 25 MPa
Media: Suitable for most chemical substances (solvents, hydrocarbons, acids, alkalis, steam, alcohol, oil)
Except for strong oxidizing acids, such as sulfuric acid and nitric acid.

Design Rationale

Many gate/globe valve manufacturers still use conventional lathes rather than full CNC machining, resulting in wider machining tolerances.
Our solution employs a “butterfly” (convex-concave) graphite ring design that:
1. Generates higher deformation force to fill larger machining gaps.
2. Requires lower gland bolt preload, ensuring reliable high-pressure sealing.
Upper-and-lower braided end rings (density 2.5–2.6 g/cm³) transmit bolt load quickly to the centre pure-graphite rings, causing immediate deformation and sealing.
Once the centre rings reach ≥1.6 g/cm³ density, the end rings then deform to complete the seal—providing a stable, self-reinforcing sealing sequence.

Key Advantages

Compensating for larger machining tolerances common in gate/globe valve production.
Low gland bolt torque requirement reduces stem binding risk.
High-density braided end rings deliver rapid load transfer and excellent anti-extrusion performance.
Full compliance with international low-emission standards.