CN206329834U - Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections - Google Patents
Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections Download PDFInfo
- Publication number
- CN206329834U CN206329834U CN201621134617.3U CN201621134617U CN206329834U CN 206329834 U CN206329834 U CN 206329834U CN 201621134617 U CN201621134617 U CN 201621134617U CN 206329834 U CN206329834 U CN 206329834U
- Authority
- CN
- China
- Prior art keywords
- bow
- shaped ring
- ring
- sealing
- longitudinal section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Gasket Seals (AREA)
Abstract
The hard seal washer of bow-shaped ring, packing ring longitudinal section is arch, and outwardly, seal line is on tortuous bow circular arc, and bowstring straight line is parallel with pipeline for tortuous bow circular arc.Land of the outer ring center provided with protrusion of land of the grip handle position of longitudinal section provided with protrusion, the i.e. hard seal washer of bow-shaped ring.Existing hard sealing ring pad elliptical ring (including octagonal ring), belongs to two-sided linear sealing, and requirement on machining accuracy is high, and price is very high, it is impossible to popularizes, can only be used in the special occasions of some HTHPs, and be only used for flange, it is impossible to be used in loose joint.Be circular arc linear sealing on the utility model sealing gasket, with terraced ring sealing system on the contrary, but bow-shaped ring be applied to save during flange and be also not required to locating slot on positioning table, flange, bow-shaped ring is particularly suitable for use in the sealing of flange.
Description
Technical field
The utility model is related to a kind of seal, belongs to chemical machinery field, more particularly, to a kind of pipeline connection
The hard seal washer of arcuate ring, a kind of and supporting welding type pipe connector of arcuate ring, including flange, clip hubbed flange and loose joint
Head, the sealing surface of pipe connections is inclined-plane (inner conical surface).
Background technology
Industrially, especially on chemical industry, pipeline connection largely uses flange.Below DN65 small-bore pipelines,
Connection is It is not necessary to use flange, it should use loose joint, and the weight of loose joint only has the 1/5~1/3 of flange, and the price of a loose joint is only
It is half of a pair of flange prices or so.Pipe connection uses loose joint, not only saves steel, expense is low, and easy for installation.Water pipe
Use zinc-plated loose joint, because leakiness at silk and pad (asbestos or rubber) are perishable, now not only on chemical industry no one use, be exactly
It is also few on waterpipe.Welded type loose joint, such as《Welded type free flow coupling standard》JB 970-77, nominal pressure
32MPa, temperature in use -25~80 DEG C, using seal by elastomeric O-ring, due to rubber non-refractory, easy aging, on chemical industry
Do not popularized, only have application in pharmaceutical industry.
Existing pipe connections are essentially all flange, and seal has asbestos board pad and metal winding Graphite pad, by
In both gasket seals can not all do it is too narrow, therefore should not be used in loose joint.Hard sealing ring pad elliptical ring (including octagonal ring), category
In dual face seals becket pad, GB GB/T 9128-2003 (steel pipe flanges becket pad size), GB are referred to
GB9130-2007 (steel pipe flanges becket pad technical conditions), (ring joint face is to welding steel by GB GB-T 9115.4-2000
Tubulation flange), high temperature high voltage resistant, but requirement on machining accuracy is very high, and price is expensive, therefore fails popularization, only in petrochemical industry high temperature
The occasion of high pressure is used.Octagonal ring pad and flange groove match, and belong to face contact, sealing effectiveness is not so good as linear sealing, but easily adds
Work, can be reused.Vesica piscis pad is linear contact lay with flange groove, and sealing is preferable, but requirement on machining accuracy is high, and not
It can reuse.Because oval ring and octagonal ring are all dual face seals, former capital is not suitable for loose joint.
The three square ring sealing gaskets that the utility model people proposes, Patent No. 201320856527.5,20152024387.0,
Belong to single facer, handling ease, manufacturing expense is low, and have self sealing action, can be used for loose joint and flange.
Utility model content
The utility model purpose is, it is proposed that a kind of new one side face seals hard seal washer or ring pad, because of section shape
Shape is arch, therefore referred to as bow-shaped ring.
Technical solutions of the utility model：A kind of hard seal washer of bow-shaped ring, it is characterized in that packing ring longitudinal section is arch, draws a bow
Outwardly, seal line is on tortuous bow circular arc, and bowstring straight line (medial surface) is parallel with pipeline for circular arc.See accompanying drawing 1.
The hard seal washer of described bow-shaped ring, land of the grip handle position provided with protrusion of longitudinal section, i.e. bow-shaped ring is sealed firmly
Land of the outer ring center provided with protrusion of packing ring.
The hard seal washer of described bow-shaped ring, longitudinal section is the deformation of arch longitudinal section, i.e. longitudinal section to be trapezoidal, trapezoidal
Outwardly, trapezoidal base angle is circular arc, and seal line is on circular arc, and the drift angle of trapezoidal waist formation is that 90~150 °, i.e. base angle is at upper bottom
15~45 °, preferably 120~140 °, i.e. base angle are 20~30 °.
Further, longitudinal section is the deformation of bow-shaped ring longitudinal section, and longitudinal section is isosceles triangle, the drift angle court of triangle
Outside, the base angle of triangle is circular arc, and seal line is on circular arc, and the drift angle of triangle is 90~150 ° (base angle is 15~45 °), most
It is 120~140 ° (base angle is 20~30 °) well, drift angle chamfering can also be orthodrome.
Longitudinal section is isosceles trapezoid, trapezoidal two kidney-shaped into drift angle be 30~120 ° (base angle is 30~75 °), preferably 60
~90 ° (base angle is 45~60 °), outwardly, the base angle of waist is acute angle or circular arc to drift angle, and material is polytetrafluoroethylene (PTFE) or other modelings
Material, linear sealing adds supplemental slanted surface to seal.
The pipe connections of the hard seal washer matching of described bow-shaped ring, including flange and articulation, pipe connections and arch
The sealing surface of ring seal washer contact is inclined-plane (inner conical surface), and the angle of inclined-plane and pipe axial direction is 15~45 °, preferably 20~
30°。
The pipe connections of described bow-shaped ring plastic seal packing ring matching, including flange and articulation, pipe connections and bow
The sealing surface of shape ring seal washer contact is inclined-plane (inner conical surface), and the angle of inclined-plane and pipe axial direction is 30~75 °, preferably 45~
60°。
For three square ring sealing systems, the sealing surface on the square ring of sealing gasket three is inclined-plane (outer conical surface), holds weldering body (method
Orchid, articulating joint, adapter) on sealing surface be circular arc (Internal Spherical Surface), the two contact forms linear sealing.Bow-shaped ring ring seal
Sealing surface on system, sealing gasket bow-shaped ring is circular arc (spherical outside surface), holds the sealing surface in weldering body (flange, articulating joint, adapter)
For inclined-plane (internal conical surface), the two contact forms linear sealing.Bow-shaped ring sealing system is the inversion of three square ring sealing systems, or says
The two on the contrary, sealing property quite, but bow-shaped ring is applied to save during flange and be also not required to gathering sill on positioning table, flange,
Bow-shaped ring is particularly suitable for use in the sealing of flange.The roughness of sealing surface, with three square rings as elliptical ring, no more than 1.6.
Described above is bow-shaped ring basic configuration, and referred to as quasi- bow-shaped ring can derive various shapes on this basis
Bow-shaped ring, but the sealing surface of various bow-shaped rings is all circular arc (spherical outside surface), is all inclined-plane (inner circle to the sealing surface for agreeing weldering body
The conical surface), linear sealing is belonged to, accompanying drawing 1~6 is seen.Generally, bow-shaped ring is divided into the major class of A, B two by us, and A is defined bow-shaped ring, B
For class triangle bow-shaped ring, A classes are divided into A1 types (accompanying drawing 1), A2 types (accompanying drawing 2) again, and it is (attached that B classes are divided into B1 types (accompanying drawing 3), B2 types again
Fig. 4) with B3 types (accompanying drawing 5), it can also derive more.Section is that the sealing ring of arch is A1 types, prolongs and axially cylindrical is cut a part of
It is afterwards A2 types bow-shaped ring (being shaped as half of elliptical ring) into plane (retaining sealing circular arc), A1, A2 type contribute to the close of loose joint
Envelope, there is positioning land the outside as three square ring sealing rings.B1 class bow-shaped rings are partly to be cut into A1 types bow-shaped ring from the outside
Lumbar triangle shape (retains sealing circular arc), and B2 class bow-shaped rings are that A1 types bow-shaped ring is partly cut into trapezoidal (reservation sealing circle from the outside
Arc), B1, B2 type contribute to the sealing of loose joint, and there is positioning land the outside as three square ring sealing rings.B1, B2 type bow-shaped ring,
Outside does not position land, is referred to as B3, B4 type, for the sealing of flange, by the self-view inclined-plane close with flange
Positioning.
The supporting pipe connections with arcuate ring, including flange and the joint of loose joint, adapter, because of the company of pipe connections and pipeline
The mode of connecing is typically all welding, therefore also referred to as holds weldering body in a standard, sees accompanying drawing 7~15.With arcuate ring is supporting holds the close of weldering body
Front cover is inclined-plane (internal conical surface), and the angle of inclined-plane and pipe axial direction is referred to as oblique angle, represented with α, and α is 15~45 °, preferably 20~
30°.Type B bow-shaped ring triangle or trapezoidal base angle represent that β is smaller than α 0.5~5 ° with β, preferably small 1~3 °.Because β is less than α, two
Individual angle differs very little again, therefore the sealing of Type B bow-shaped ring is based on linear sealing, supplemented by the sealing of face, and in flange (loose joint)
Sealing ring has self-locating function during tightening, and can remove positioning land in design, and the design of flange does not have gathering sill yet,
This structure is particularly suitable for use in flange.
Bow-shaped ring sealing gasket is compared with three square ring sealing gaskets, and another advantage is that dead volume is small, because of the seal line of bow-shaped ring
In ring end, the seal line of three square rings is in the middle part of ring, therefore flange (loose joint) the liquid holdup volume for using bow-shaped ring to seal is few, this
A little especially important to pharmaceutical industry, three square rings cannot be used for greatly pharmaceutical industry because of liquid holdup volume.
From in shape, bow-shaped ring is the mutation of elliptical ring (octagonal ring), and A type bow-shaped rings section is half of elliptical ring, Type B
Bow-shaped ring section is half of octagonal ring, but actually bow-shaped ring and elliptical ring (octagonal ring) are essentially different.One, elliptical ring
(octagonal ring) is dual face seals, and sealing ring just will be put into the annular groove of flange, requires high to accurate to dimension, bow-shaped ring is
Single facer, requires low to accurate to dimension.Two, elliptical ring (octagonal ring) is sealed by crimp, it is desirable to which material is mild steel,
Elliptical ring can only be with once, and bow-shaped ring has function of self-tightening, is sealed by the screen resilience of metal and the tension force of internal pressure after deformation is tightened,
Material mild steel is not required, just can be with common iron, it is generally used for holding weldering body identical material, and also bow-shaped ring can be repeatedly
It is used for multiple times, experiment proof can be used more than 1000 times.Three, due to bow-shaped ring have function of self-tightening, it is necessary to pretightning force it is small, lead to
Saying for custom is exactly gently high pressure resistant on one, is equally difficult to tighten (therefore could not promote out always) rather than ball face sealing loose joint.
Four, Type B bow-shaped ring has self-locating function, and is face sealing unlike octagonal ring, be based on linear sealing, face is sealed into
Auxiliary, face sealing is unreliable, and this is also one of the reason for octagonal ring can not be promoted.
The material of arcuate ring is generally metal, general using with holding weldering body identical material, can also use enhancing polytetrafluoro
The plastics such as ethene or polypropylene.
In order to solve the problem of hard sealing surface is destroyed after corrosion of carbon steel, the utility model also proposed a kind of c-type bow-shaped ring,
See Fig. 6, Figure 13 is shown in using the installation diagram of c-type bow-shaped ring sealed active connected, articulation seal groove bevel angle α is 30~75 °, preferably 45
~60 °.Seal ring material typically uses carbon fiber reinforced ptfe (black), and low temperature and low corrosion condition can also be used
Polypropylene, medicine and food service industry use flexible high-quality polytetrafluoroethylene (PTFE) (white), the bow-shaped ring of carbon steel material and supporting
Pipe connections must carry out antirust treatment.Because the plastics that sealing ring is used have certain elasticity, and shape and plain cushion are different, can
With Reusability, small-bore pipeline is primarily adapted for use in.
Beneficial effect：Bow-shaped ring is used for loose joint, flange and clamping (clip pipe connections), is not only used for pipeline connection
On, the also connection including valve.Existing valve, can be changed to the joint (to smaller diameter valve) of bow-shaped ring sealed active connected, or arch
The sealed flange of ring or clamping (to large bore valves).The utility model small volume, can form tight face and seal, low cost,
Pipe connections are installed convenient.
Bow-shaped ring is most adapted to the connection of stainless steel pipes, bow-shaped ring and all uses stainless steel with casing joints.For
Carbon steel pressure piping, bow-shaped ring sealing is also optimal selection, the bow-shaped ring of carbon steel material and must carry out antirust with casing joints
Processing, such as nigrescence, phosphatization, zinc-plated, zinc electroplating with iridescent yellow chromate conversion coating and nickel-plated phosphor.
The utility model proposes the hard seal washer-bow-shaped ring of single facer, from held unlike three square rings weldering body (flange,
Articulating joint, adapter) on sealing surface be inclined-plane, be circular arc linear sealing on sealing gasket, with terraced ring sealing system on the contrary, this knot
Structure sealing property is suitable with three square rings, but bow-shaped ring is applied to save during flange and be also not required to locating slot on positioning table, flange,
Bow-shaped ring is particularly suitable for use in the sealing of flange.
The utility model proposes bow-shaped ring sealing ring, can make to be actively socketed on and industrially be popularized, to small diameter metal
The connection of pipe (below DN65) can substitute the flange that generally uses now completely, can save manufacture the steel 60 of pipe fitting~
70%, installation period can also be reduced.For the connection of large diameter pipeline, bow-shaped ring sealing is also advantageous, at least can be used for
The connection of stainless steel pipes and high-temperature and pressure pipeline.
Brief description of the drawings
Fig. 1 is A1 type bow-shaped ring schematic diagrames.
Fig. 2 is A2 type bow-shaped ring schematic diagrames.
Fig. 3 is B1 type bow-shaped ring schematic diagrames.
Fig. 4 is B2 type bow-shaped ring schematic diagrames.
Fig. 5 is B3 type bow-shaped ring schematic diagrames.
Fig. 6 is c-type bow-shaped ring schematic diagram.
Fig. 7 is that figure is taken in loose joint.
Fig. 8 is articulating joint figure.
Fig. 9 is loose joint nut figure.
Figure 10 is A1 type bow-shaped ring sealed active connected assembling figures.
Figure 11 is B1 type bow-shaped ring sealed active connected assembling figures.
Figure 12 is B3 type bow-shaped ring sealed active connected assembling figures.
Figure 13 is c-type bow-shaped ring sealed active connected assembling figure.
Figure 14 is bow-shaped ring sealing flange assembling figure.
Figure 15 is that bow-shaped ring seals clamping assembling figure.
The meaning of each label is as follows in figure：
D-bow-shaped ring internal diameter, takes bore or close to bore；
d1- bow-shaped ring external diameter；
d2- sealing ring seat slot diameter；
d3- tube seat diameter；
d4- nut aperture；
D-butt welding end pipe external diameter；
D1- positioning circular diameter；
D2The locating ring external diameter of-sealing ring；
H-bow-shaped ring is highly；
h1- locating ring is highly；
M-screw thread engineering diameter；
R-bow radius of circle；
R1- Type B bow-shaped ring end arc radius；
R2- transition arc radius；
The side's opposite side distance of S-nut six；
The angle of α-seal ring seat (groove) oblique angle, groove inner conical surface and axle；
β-ring oblique angle, Type B bow-shaped ring triangle or trapezoidal base angle, equal to sealing ring male cone (strobilus masculinus) and the angle of axle.
Embodiment
Embodiment 1
DN25PN63 loose joints, sealing gasket is A1 type bow-shaped rings, sees Fig. 1,10, R=15mm, α=23 °, h=14mm, h1=
2mm, remaining size is identical with the square ring loose joints of DN25 tri-, refers to China Patent No. 201320856527.5,20152024387.0.
Bow-shaped ring, joint, the material of adapter are stainless steel 304, and nut material is that 20# carbon steels are zinc-plated.0.5 meter of φ is welded on connector and adaptor
32 × 3 steel pipes, Guan Yitou connects pressure gauge, and one connects the cutting ferrule valves of φ 10.Upper gland, with nitrogen cylinder from cutting ferrule valve suppress to
10MPa, closes cutting ferrule valve, the connecting leg of dismantle nitrogen cylinder and cutting ferrule valve.Loose joint is immersed in the water, observed 10 minutes, without bubble.
Place 5 hours, pressure does not change.Proof is not leaked.
Embodiment 2
DN25PN63 loose joints, sealing gasket is B1 types bow-shaped ring (Fig. 3), α=23 °, β=21 °, R1=1.6, R2=1, remaining
With example 1, Figure 11 is shown in installation.Bow-shaped ring, joint, the material of adapter are stainless steel 304, and nut material is that 20# carbon steels are zinc-plated.Such as example
1 connects loose joint, is suppressed with manual pressure test pump, water inlet to 20MPa, closes cutting ferrule valve.Observation 5 hours, no water oozes out, pressure
Also do not change.
Embodiment 3
DN25PN25 loose joints, sealing gasket is c-type bow-shaped ring (Fig. 6), α=60 °, β=57 °, R1=0.5, adapter, joint are close
Figure 13 is shown in front cover and installation.Joint, adapter and nut material are that 20# carbon steels are zinc-plated, and arch ring material is fibre reinforced poly- four
PVF.Such as example 1 connects loose joint, is suppressed with manual pressure test pump, water inlet to 5MPa, closes cutting ferrule valve.Observation 5 hours, does not have
Water oozes out, and pressure does not also change.
Embodiment 4
The flange sealed using bow-shaped ring, is shown in Figure 14, flange specification DN150DN63, and material is 20# carbon steels, blackening process.
Using B3 type bow-shaped rings, material is 20# carbon steels, blackening process, α=23 °, β=21 °, ring external diameter φ 164mm, h=15mm, R1
=1.6mm.Test pressure 20Mpa, medium is nitrogen, airtight 24h No leakages.
Claims (7)
1. a kind of hard seal washer of bow-shaped ring, it is characterized in that packing ring longitudinal section is arch, tortuous bow circular arc outwardly, drawing a bow by seal line
On circular arc, bowstring straight line is parallel with pipeline.
2. the hard seal washer of bow-shaped ring according to claim 1, land of the grip handle position provided with protrusion of longitudinal section, that is, bend
Land of the outer ring center provided with protrusion of the hard seal washer of shape ring.
3. the hard seal washer of bow-shaped ring according to claim 1, it is characterized in that longitudinal section is the deformation of arch longitudinal section, i.e.,
Longitudinal section is trapezoidal, and outwardly, trapezoidal base angle is circular arc, and seal line is on circular arc, the drift angle of trapezoidal waist formation at trapezoidal upper bottom
It it is 15 ~ 45 ° for 90 ~ 150 °, i.e. base angle.
4. the hard seal washer of bow-shaped ring according to claim 1, it is characterized in that longitudinal section is the deformation of bow-shaped ring longitudinal section,
Longitudinal section is isosceles triangle, and outwardly, the base angle of triangle is circular arc to the drift angle of triangle, and seal line is on circular arc, triangle
Drift angle be 90 ~ 150 °.
5. the hard seal washer of bow-shaped ring according to claim 1, it is characterized in that longitudinal section is isosceles trapezoid, trapezoidal two kidney-shaped
Into drift angle be 30 ~ 120 °, outwardly, the base angle of waist is acute angle or circular arc to drift angle.
6. using the pipe connections matched with the hard seal washer of bow-shaped ring described in one of claim 1-5, it is characterized in that including
Flange and articulation, pipe connections are inclined-plane i.e. inner conical surface, inclined-plane and pipe axial direction with the sealing surface that bow-shaped ring seal washer is contacted
Angle be 15 ~ 450。
7. using pipe connections match with the bow-shaped ring plastic seal packing ring described in one of claim 1-5, it is characterized in that wrapping
Flange and articulation are included, pipe connections are inclined-plane i.e. inner conical surface, inclined-plane and pipe axle with the sealing surface that bow-shaped ring seal washer is contacted
To angle be 30 ~ 750。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621134617.3U CN206329834U (en) | 2016-10-18 | 2016-10-18 | Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621134617.3U CN206329834U (en) | 2016-10-18 | 2016-10-18 | Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206329834U true CN206329834U (en) | 2017-07-14 |
Family
ID=59286854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621134617.3U Expired - Fee Related CN206329834U (en) | 2016-10-18 | 2016-10-18 | Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206329834U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018072522A1 (en) * | 2016-10-18 | 2018-04-26 | 杨顺立 | Annular hard sealing washer having bow-shaped section and sealing tube connector |
-
2016
- 2016-10-18 CN CN201621134617.3U patent/CN206329834U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018072522A1 (en) * | 2016-10-18 | 2018-04-26 | 杨顺立 | Annular hard sealing washer having bow-shaped section and sealing tube connector |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106352181A (en) | Arched ring seal washer and arched ring seal pipe connecting piece | |
| CN203756982U (en) | Triangular ring sealing gasket and loose joint adopting triangular ring sealing gasket | |
| CN206329834U (en) | Bow-shaped ring seal washer and bow-shaped ring sealing pipe connections | |
| CN216242786U (en) | Corrosion-resistant petroleum pipeline joint | |
| US4555129A (en) | Adapter union and improved adapter member therefor | |
| CN204717181U (en) | Modified model three square ring seal washer and modified model three square ring sealed active connected and flange | |
| CN202349428U (en) | Pipeline connector | |
| CN117450347A (en) | Chemical industry is with compound ABR pipe and sealing connection structure thereof | |
| CN210564386U (en) | Take anticorrosive sucker rod of full cladding of stainless steel joint | |
| CN211423671U (en) | High-sealing corrosion-resistant RTP joint | |
| CN212616847U (en) | Corrosion-resistant connecting joint for oil and gas conveying non-metallic pipeline | |
| US20230400113A1 (en) | Internally-sealed one-piece external thread ball valve | |
| JP2019019834A (en) | gasket | |
| CN107893888A (en) | A kind of snap joint | |
| CN112524379A (en) | Stainless steel elbow with screw mouth lining | |
| CN219062706U (en) | High pressure-resistant threaded joint | |
| CN220416366U (en) | Sealing node structure of container valve and pressure gauge | |
| CN219639737U (en) | High leakproofness tee bend pipe fitting | |
| CN221443599U (en) | Hard seal loose joint | |
| CN220506077U (en) | Sealing flange convenient to block | |
| CN213541577U (en) | Composite pipe connecting joint | |
| CN215487745U (en) | PE end elastic sealing gas gate valve | |
| CN220668686U (en) | Butt joint pipeline assembly | |
| CN212080535U (en) | Novel pipeline connecting structure | |
| CN218719410U (en) | High-temperature-resistant polyethylene heat-insulating pipe |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170714 Termination date: 20211018 |