Mainly used for the sealing of valves, pumps, expansion joints, etc. in petroleum, chemical, thermoelectric, nuclear power and general industrial applications. Used for stem seals such as low leakage rate shut-off valves, isolation valves, and regulating valves.

Applications

Working temperature: -196°C～600°C
Working pressure: ≤43.1MPa

Transportation and Storage

Prevent rain and moisture during transportation.
Should be stored in a clean, dry warehouse.

Technical Parameters

Installation Instructions

Place the packing ring in the stuffing box, preload with gland bolts, compress the entire packing assembly by 15% to 20%, and record the torque of the gland nut. Then turn the valve stem for 5 switching cycles. After each rotation, tighten the gland nut to the previously recorded torque value.

Main products

Package Ring Use Maintenance and Operation Maintenance

Causes of sealing failure

Volume loss and brittleness during use of woven fillers
Damaged packing ring during installation
Lack of cover load
Poor thermal shock resistance of filler
Filler wear, slack, volume loss results in reduced lid load
Packing ring size deviation is too large
The depth of the stuffing box design is irrational
Shaft (bar) surface is rough
Axis (bar) and stuffing box are different
Spindle (rod) erosion or filler wear in operation

Use maintenance

Correct design of stuffing box size
Carefully install the packing ring
Packing box depth meets design specifications
Shaft (bar) surface should be smooth
Proper gland loading and load adjustment capability
There are measures to compensate for the wear of the packing, such as gland nuts and disc spring washers
Shaft (rod) has good support
Packing and stuffing box have the correct fit clearance
Correctly install and compress the packing before running.

Operation and maintenance

1. After the seal packing is assembled, it can be put into operation. Before the official start of the car, you should start the test run slowly with human power. In operation, if the torque is too large, it may be caused by the tightness of the packing gland. It may be appropriate to loosen the gland bolt and adjust it until the frictional resistance becomes smaller without leakage.
When starting operation, if the friction torque is large and the temperature of the stuffing box rises, the preload may be too great. Measures must be taken to adjust and, where circumstances permit, appropriate leakages should be controlled. For most non-harmful media centrifugal pumps, a small amount of droplet leakage should be maintained in normal conditions to provide cooling and lubrication.
2, after the official drive, we must adhere to observe on time, pay attention to whether the leakage and the temperature of the stuffing box meet the requirements, if any abnormalities, to immediately adjust. If the leakage is greater than the allowable value, the gland can be tightened.
3, storage of filler
1) The sealed packing should be stored in a normal temperature, ventilated place; prevent direct sunlight, in order to avoid aging deterioration. It must not be stored in the vicinity of corrosive materials such as acids and alkalis, nor should it be stored in high-temperature radiation or in low-temperature and humid environments.
2) During handling and inventory, care should be taken to prevent sand, dust and foreign matter from sticking to the packing. Once the debris is adhered, it must be completely removed to avoid damage to the shaft surface after assembly and affect the sealing effect.
3) For the sealed packing used in nuclear power plants, in addition to the above points, care should be taken to avoid contact with substances containing chloride ions.

Pre-tightening force estimation method for bolts

M = 0.785(D2-d2) × d_B × F/n
dB – nominal diameter of bolt (mm)
F – bolt load (MPa) braided packing by 38MPa, graphite packing ring by 26MPa, or by 1.5 times the medium pressure
N – number of bolts

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RBT–non-metallic fiber reinforced flexible graphite braided filler
RBTN–Internal non-metallic and metal-reinforced flexible graphite woven filler
RBTW – External Metal Reinforced Flexible Graphite Woven Filler
RBTH–Flexible Graphite Woven Filler Moulding Ring

Usage

Can be used for boiling water, high temperature, high pressure steam, heat exchange liquid, oil, acid and alkali, hydrogen, ammonia, organic solvents, hydrocarbons, cryogenic liquids and other media. Widely used in petroleum, chemical, electric power, metallurgy, machinery, paper and other industries of centrifugal and reciprocating pumps, valves, pipes and other seals.

Transportation and Storage

Prevent rain and moisture during transportation.
Should be stored in a clean, dry warehouse.

The sealing principle

The reason why woven packing can play a role in sealing is mainly the bearing effect and the labyrinth effect.
The bearing effect of braided packing means that a layer of liquid film is formed between the braided packing and the shaft due to the tension, so that the braided packing and the shaft form a similar relationship to the sliding bearing so that the braided packing and the shaft are not excessively rubbed. And wear occurs.
The labyrinth effect of braided packing means that the surface of the shaft is virtually always uneven, and the packing and the shaft can only partially fit and do not completely fit together. There is always an extreme between the braided packing and the shaft. With tiny gaps, these gaps form labyrinth belts in which the medium is throttled several times to achieve sealing.

Main products

Appearance

Flexible graphite braided packing should have a well-proportioned pattern, a smooth surface, no exposed threads, no particulate matter or foreign matter, and flexible graphite braided fillers
Molded press rings should have no delamination, flat interfaces, no looseness, and clean surfaces with no impurities.

Dimensional Deviation

Flexible graphite braided packing cross-sectional dimension limit deviation unit:mm

Flexible Graphite Braid Filler Molded Ring Size Limit Deviation Unit: mm

Performance

Test

Appearance was visually inspected.
Flexible graphite woven filler dimensional deviation, apparent density, 450 °C thermal weight loss, compression rate, rebound rate test according to JB/T 6620.
Flexible graphite braided fillers The 600 °C thermal weight loss test was carried out according to JB/T 6620. The test temperature was (600 ± 10) °C.
Sulfur content inspection of flexible graphite woven packings is carried out according to GB/T24526.
The dimensional deviation, apparent density, compressibility, and rebound rate of the molded rings of flexible graphite braided packings were measured in accordance with JB/T 6370.

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