HLG550 spring reinforced metal sealing ring
Structure and principle
The spring-strengthened metal sealing ring is composed of an outer layer of soft coating material or coating, an inner liner made of metal material, and a wrapped spiral close-wound spring. When the sealing ring is locked and compressed, the elastic force of the spiral spring acts on the inner lining to fit the flange sealing surface, and the soft material or coating layer covered by the outer layer fills up the roughness of the flange surface and prevents the leakage channel between the end surfaces. Produce, and finally achieve an excellent sealing effect.
Main features
• Scope of application:
Diameter: from 5mm to 7m, cross section from 1.7mm to 10mm or larger;
Temperature: ultra-low temperature to 980°C;
Pressure: from vacuum to 300Mpa;
• Compression resilience: The spring-strengthened metal sealing ring has excellent flange surface compensation performance under alternating temperature and pressure conditions, and the compression rate can reach 20%;
• Low pretension;
• Excellent resistance to relaxation;
• Excellent corrosion resistance and radiation resistance;
• Suitable for most standard flanges or non-standard flanges or special structures;
Materials used
• Lining and covering
| Part | Material | delivery status | hardness | Reference standard |
| Inner lining and outer covering | Stainless steel 304, 316, 321 | Solid solution | ≤92HRB | GB/T 3280s ASTM A240 |
| Nickel N200 | annealing | ≤70HRB | GB/T2054, ASTM Bl 62 | |
| Nickel alloy 600, nickel alloy 800 | annealing | ≤92HRB | ASTM B 168、ASTM B 409 | |
| Aluminum 1050A | annealing | ≤25 HV | GB/T 3880 | |
| Copper T2, Monel | annealing | ≤70 HV | GB/T 2040、GB/T 5231 | |
| Gold, silver | 99.90% purity | |||
• Plating or coating
| part | skills requirement | Reference standard |
| Gold, silver, nickel | Purity≥99.9 | |
| PTFE, graphite or others | Depends on working conditions | As required |
• Coil spring
| part | Material | Reference standard |
| spiral | Stainless steel 304, 316, 321 | GB/T4356、JIS G4314 |
| spring | Nl-Fe-Cr X750 | ASTM B 637 |
use pressure
Determine the working pressure of the sealing ring according to the C-shaped opening direction of the spring-strengthened metal sealing ring. When the C-shaped opening faces the pressure direction, a self-tightening sealing effect can be achieved, and the pressure that can be withstood can also be greatly increased. However, when choosing whether the C-shaped opening faces the pressure direction, the choice of medium type and coil spring material should be considered.
| Non-media-oriented | Medium-oriented |
| High vacuum~7Mpa | Vacuum ~300Mpa |
Model classification
Diagram
Performance curve
After the installed spring-reinforced metal sealing ring reaches the set compression amount, it can maintain a certain rebound during the working process. This compensation performance ensures that the sealing surface can always fit during the temperature and pressure changes. . For the convenience of installation, the spring-reinforced metal sealing ring works under the condition of a limited position, which also avoids uneven force, excessive compression or insufficient compression.
The diagram shows the relationship between the load and leakage when the spring-strengthened metal seal is compressed and decompressed. It is mainly composed of two curves, one is the compression curve and the other is the decompression curve.
The inherent ability of the sealing ring
A characteristic of spring-strengthened metal sealing ring is called inherent ability, which reflects its ability to balance internal pressure and relaxation through its own elasticity at a given temperature. The characteristic symbol is represented by Pu, and the unit is N/mm². The figure below reflects the influence of temperature on Pu. In the figure, Pu and Put respectively represent the Pu values at 20°C and operating temperature T, and the following table lists these inherent capacity values of spring-strengthened metal sealing rings. ...
...
According to the value in the table, the compressive load Wm2=W₂XP/Pᵤ, N/mm required for the seal ring to seal the internal pressure at room temperature can be obtained; where P is the operating pressure or test pressure; then the seal is sealed at the operating temperature The compressive load on the unit seal length required by the internal pressure Wm2T=W₂XP/Put. N/mm; and the P/Pᵤ or P/PUT<1 in the formula. Therefore, the material and the thickness of the sealing ring can be adjusted according to the pressure and temperature during the design. Make a match.
| Inherent capacity value of sealing ring (ammonia) | |||||||||||||
| Section diameterd mm | aluminum N/mm | silver N/mm | copper N/mm | ||||||||||
| Pᵤ 20°C | Put200°C | Pᵤ 20°C | Put250°C | Pᵤ 20°C | Put300°C | ||||||||
| 1.7 | 52 | N/A | 66 | N/A | 52 | 10 | |||||||
| 2.6 | 56 | 6 | 76 | 8 | 60 | 16 | |||||||
| 3.8 | 58 | 16 | 100 | 25 | 72 | 28 | |||||||
| 5.6 | 66 | 24 | 140 | 42 | 90 | 35 | |||||||
| 8 | 71 | 30 | 174 | 62 | 104 | 45 | |||||||
Seal pre-tightening force
Parameter definition
F Total bolt load applied，N;
Fc The total load when the seal ring is pre-tightened to the specified amount of compression，N;
F0 The total load applied to the bolt to maintain the seal during operation，N;
Fp Total axial load generated by internal pressure，N;
Dr Diameter of the contact position of the sealing ring，mm;
Fm Minimum total load to maintain the seal during operation，N;
Eb Young's modulus of bolt material at 20°C，N/mm²;
EbtYoung's modulus of bolt material at operating temperature，N/mm²;
Calculation formula
When F₀ × Eb/Ebt> Fc, then F=F₀ × Eb/Ebt
When F₀ × Eb/Ebt <Fc, then F=Fc
in
Fc=∏DrW₂，N;
F0=Fm+FP, N; When PDr≥32Wm, Fc should be used instead of Fm, then F0=FC+FP;
FP=Dr2Wm × ∏/4，N;
Fm=∏DrWm, N; Wm is the larger value of Wm1 and Wm2;
In order to achieve the best sealing effect, the following provides a table of the linear load characteristics of the spring-strengthened metal sealing ring. When designing the sealing joint, the designer will match according to the recommended values in the table, and consider the relaxation, pressure, vibration and impact of the bolt under high temperature to retain an appropriate safety factor.
| Linear load characteristic value table (chlorine gas) | ||||||||
|
Section diameter |
Inner diameter D |
Groove depth |
aluminum N/mm |
Silver, copper N/mm |
Nickel, Monel N/mm |
|||
|
W2 |
Wm1 |
W2 |
Wm1 |
w2 |
Wm1 |
|||
|
1.7 |
5-50 |
1.4 |
160 |
20 |
220 |
30 |
250 |
60 |
|
2.6 |
10〜100 |
2.1 |
220 |
30 |
250 |
45 |
340 |
70 |
|
3.8 |
25-1500 |
3 |
250 |
35 |
310 |
55 |
490 |
110 |
|
5.6 |
150-2000 |
4.5 |
320 |
45 |
390 |
70 |
640 |
150 |
|
8 |
>200 |
7 |
340 |
50 |
490 |
90 |
800 |
185 |
|
10 |
>200 |
9 |
390 |
60 |
590 |
110 |
- |
- |
| Linear load characteristic value table (ammonia) | ||||||
| Section diameter d mm |
the inside diameter of D mm |
Groove depth h mm |
Stainless steel | Nickel alloy | ||
| w2 | Wml | W2 | Wml | |||
| 1.7 | 5~50 | 1.4 | 290 | 80 | 350 | 100 |
| 2.6 | 10-100 | 2.1 | 400 | 100 | 460 | 115 |
| 3.8 | 25-1500 | 3 | 590 | 130 | 690 | 160 |
| 5.6 | 150-2000 | 4.5 | 780 | 155 | 900 | 250 |
| 8 | >200 | 7 | 950 | 180 | 1100 | 340 |
| 10 | >200 | 9 | - | - | - | - |
the seal groove
Parameter definition
C2Is the compression of the sealing ring (ie d-h), mm;
J is the radial clearance between the outer diameter of the sealing ring and the outer wall of the groove，mm;
A is the outer diameter of the sealing groove，mm;
C is the inner diameter of the seal groove，mm;
h is the depth of the seal groove or the thickness of the limit ring，mm;
d is the cross-sectional diameter of the sealing ring，mm;
B is the outer diameter of the sealing ring，mm;
D is the inner diameter of the sealing ring，mm;
L is the bolt hole diameter，mm;
G is the bolt center distance，mm;
E is the inner diameter of the bolt hole，mm;
F is the pitch diameter of the sealing ring，mm;
With restriction ring h=d-C2, E=G-L-2
・Size Chart
| Section diameter d mm |
Size range D mm |
Groove depth h mm |
Internal pressure p<2Mpa | Internal pressure p≥2Mpa | Under vacuum | |||
| Groove outer diameter A mm | Slot inner diameter c mm | Groove outer diameter A mm | Slot inner diameter c mm | Groove outer diameter A mm | Slot inner diameter c mm | |||
| 1.7 | 5~50 | 1.4 | D+3.9 | D-0.7 | D+3.7 | D-0.9 | D+3.6 | D-0.8 |
| 2.6 | 10〜100 | 2.1 | D+5.9 | D-0.9 | D+5.5 | D-1.3 | D+6.0 | D-0.8 |
| 3.8 | 25-1500 | 3 | D+8.6 | D-1.4 | D+8.1 | D-1.9 | D+9.0 | D-1.0 |
| 5.6 | 150-2000 | 4.5 | D+12.3 | D-3.7 | D+11.7 | D-4.3 | D+15.0 | D-1.0 |
| 8 | >200 | 7 | D+17.0 | D-7.0 | D+16.7 | D-7.3 | D+23.0 | D-1.0 |
| 10 | >200 | 9 | D+21.0 | D-9.0 | D+20.7 | D-9.3 | D+28.0 | D-2.0 |
・Radial tolerance range
| Seal ring size range D (mm) |
p<2Mpa | p≥2Mpa | ||
| f | t | f | t | |
| 5〜50 | 0.15 | 0.15 | 0.1 | 0.1 |
| 50-300 | 0.25 | 0.25 | 0.1 | 0.1 |
| 300〜650 | 0.25 | 0.25 | 0.15 | 0.15 |
| 650〜1500 | 0.5 | 0.5 | 0.3 | 0.3 |
| >1500 | 0.8 | 0.6 | 0.8 | 0.6 |
・Tolerance range of groove depth
| Section diameter d(mm) | 1.5~2.6 | 27~5.0 | 5.1~10.0 |
| Tolerance of groove depth h(mm) | ±0.06 | ±0.10 | ±0.13 |
・Relationship between media type, surface treatment and seal groove/surface roughness
| Media type | Seal groove/surface roughness (Ra) | ||
| Electroplating treatment | PTFE treatment | No spray | |
| Vacuum and gas (volatile) | 0.4 | 0.8 | Not applicable |
| Water, steam, solution (low viscosity) | 0.4 | 0.8 | 0.4 |
| Oil, plastic, etc. (high viscosity) | 0.8 | 1.6 | 0.8 |
・Relationship between coating material and seal groove/surface roughness
| Material | aluminum | Silver, copper | Fetter | Stainless steel | Fetter Alloy |
| Seal groove/surface roughness (Ra) | 0.8 | 0.4 | 0.2 | 0.2 | Coating |
・Three-sided seal
Parameter definition
a is the angle of the sealing slope，° ;
J is the radial distance between the shaft and the sealing slope，mm;
h is the radial distance of the inclined plane，mm;
E is the outer diameter of the shaft，mm;
A is the inner diameter of the sealing ring，mm;
e is the axial compression，mm;
W2' is the axial linear stress，N/mm;
d is the cross-sectional diameter of the sealing ring，mm;
C2 is the specified axial compression of the sealing ring，mm;
・Radial tolerance range
| size | Shaft outer diameter E | Seal ring inner diameter A |
| tolerance | +0, -0.05 | +0.05，-0 |
・Coefficient value
| Coefficient | a=30° | A=45° |
| m | 2 | 1.4 |
| n | 0.9 | 1.2 |
·calculate
W2'=nW2 E=A J=d/10 e=mC2
・Sealing criteria
The sealing leakage rate of the spring-strengthened metal sealing ring is designed by a series of flanges, bolts, sealing surfaces, surface treatments, etc., after the relevant test process, the required sealing goal is finally achieved.
Nitrogen leakage rate: the sealing leakage rate does not exceed 1×lO⁻⁹std.cc/sec, the temperature is normal temperature, and the medium pressure is 1bar;
Other requirements: due to different working conditions, other related tests can be carried out after confirmation with the manufacturer;
・Sealing ring selection
The spring-strengthened metal sealing ring is not only suitable for special structures and non-standard flanges, but also suitable for a variety of standard flange structures, such as ASMEB16.5, EN1092 flanges, and its structure can be raised, concave and convex, full plane, Tongue and groove surface. Its temperature resistance, aging resistance and corrosion resistance make it a substitute for rubber O-rings. Compared with metal spiral wound gaskets, toothed gaskets, metal sheathed gaskets, etc., it has better sealing performance And compensatory.
Related Products
The maximum working pressure can reach 42.0MPa.
The maximum operating temperature can reach 600°C.
Maximum operating temperature: oxidizing gas: 450°C; non-oxidizing gas: 800°C.
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