CN202327345U - Low-friction high-pressure-resistant valve-rod seal ring - Google Patents

Abstract

The utility model relates to a low-friction high-pressure-resistant valve-rod seal ring and relates to a valve sealing device in the drilling and production process of petroleum and gas. The technical scheme includes that a filler seat ring is arranged below the low-friction high-pressure-resistant valve-rod seal ring, a filler press cover is arranged above the low-friction high-pressure-resistant valve-rod seal ring, the whole low-friction high-pressure-resistant valve-rod seal ring is annularly arranged between a valve rod and a valve cover to have sealing effects and comprises the seal ring and a pre-tightening spring, wherein one side of the seal ring is recessed inwards to form an annular groove, and the pre-tightening spring is clamped in the annular groove and exerts elasticity on two side walls of the annular groove to drive the two side walls of the annular groove to exert pressure on the valve rod and the valve cover. The portions of the seal ring contacted with the valve rod and the valve cover are in a zigzag structure, and a certain floating gap is reserved between the seat ring and the filler press cover. The seat ring can guarantee sealing performance well, the opening torque and the closing torque which are needed when the valve rod is opened and closed are extremely small so that a valve can be opened and closed fast and easily.

Description

The high pressure resistant valve stem packing ring of a kind of low friction

Technical field

The utility model relates to used valve sealing device in a kind of petroleum gas drilling process, particularly relates to a kind of valve stem packing ring with low friction high voltage performance.

Background technique

The valve of employed various types of high pressure even ultrahigh pressure in petroleum gas drilling production and the conveying; Throttle well killing pipeline, blowout prevention pipeline, relief line and other well control equipment, the effective cooperation work of device that need the high-voltage and ultra-high valve to be formed; Could guarantee that petroleum gas drilling work safety normally carries out, and avoids and control the generation and the development of serious accident.In other words, this type valve is to be used for high pressure even ultrahigh pressure, flammable and explosive substance, the on-the-spot well control of oil field drilling! So, natural, this type valve has been proposed extremely strict various performance requirements.And in these performance requirements, mainly contain two: one is reliable sealing performance under this type of working state, and another controls performance exactly reliably under various extremities.

The valve seal performance is meant the ability that each sealed department steric hindrance of valve is ended dielectric leakage.The main sealing position of valve has: the joint of the cooperating of the matching surface of open-shut device and valve base chamber, filler and valve rod and stuffing box, valve body and valve gap.The leakage at first place is interior leakage, and it directly influences the ability of valve cross section medium and the normal operation of equipment.The leakage at two places, back is leaking outside, and promptly outside valve, it directly influences safety in production to medium from the valve internal leakage.Cause working medium loss and business economic loss, environmental pollution, can cause production accident when serious.For high pressure, inflammable and explosive, poisonous or corrosive medium, leaking outside of valve is unallowed at all especially, so valve must have reliable sealing performance, satisfies it and uses the requirement of industrial and mineral to leakage rate.

Valve is meant controling performance under the various extremities reliably: in petroleum gas drilling process, if when well kick, blowout, fire take place, possibly also exist borehole pressure very high this moment; The pipeline distortion, pipeline high vibration, place confusion or the like urgency; Under this situation of speedily carrying out rescue work, valve is the ability of opening and closing rapidly and effectively, launches accurately and effectively rapidly to guarantee various well control rescues; The person will not cause unmanageable situation.

Valve rod is to drive open-shut device to make valve opening and the vitals of closing, because valve rod is a movable piece.So be the position that the easiest generation leaks outside, because be to drive open-shut device to make valve opening and the vitals of closing, so be again the main agent of handling.Therefore, valve stem seal is very important for valve.

Valve stem seal normally adopts the gland packing sealing, and its packing seal principle is:

Gland carries out axial compression to filler in the stuffing box, and the moulding of filler makes it produce radial force, and closely contacts with axle.Simultaneously, the oiling agent that adds in the filler is extruded, and between surface of contact, forms oil film.Because contact condition is inhomogeneous, boundary lubrication condition appears in the contact position, and the recess of contact does not form little oil groove, and thicker oil film is arranged.When axle and filler had relative movement, irregular labyrinth was formed with contact position not in the contact position, plays the effect that stops flow to be leaked.

Customary fillers has: asbestos packing (oil immersion asbestos packing), teflon braiding packing, rubber folder cloth or plastic shaping filler: generally make three-member type.Used plastics are many with teflon, also have to adopt nylon.The plastic, rubber composite filling: plastics are many with teflon, also have to adopt nylon, and rubber mainly is the high elasticity oil resistant rubber.

In the existing valve seal, in order to guarantee the sealing of filler to interior media, must guarantee filler seat ring place, filler bottom filler to the radial pressure of valve rod greater than the pressure medium that is sealed.For reaching this purpose; Must apply very big preload pressure to filler through Gland; It is especially true to reach the bigger situation of friction factor more greatly for packed height, and the pressure medium (well pressure often) that is sealed is big more; Radial pressure requires also big more, and the preload pressure that filler is applied will be bigger! This will cause very big surface friction drag, and needed opening and closing torque force is very big when causing the valve rod opening and closing, makes the opening and closing valve very slow, and is very painstaking, causes valve rod by locking sometimes, just can't open and close at all! Have a strong impact on and delay carrying out of well control rescue! And can quicken the wearing and tearing of filler and valve rod.If the preload pressure that filler is applied is not enough, just can not satisfy filler seat ring place, filler bottom filler to the radial pressure of valve rod greater than the pressure medium requirement that is sealed, just have and sealing take place incessantly, thereby produce serious danger of leaking.In addition, pure teflon has tangible cold flow properties after pressure surpasses 40MPA, so pure polytetrafluoroethylene packing can not be used for the valve stem seal that pressure surpasses 40MPA; And nylon under high pressure its heat distortion temperature is very low, can't satisfy needed intensity of high pressure sealing material and hardness requirement.

The model utility content

The purpose of the utility model is to solve prior art problems; Provide a kind of low friction high pressure resistant valve stem packing ring; The sealing circle can be good at guaranteeing sealability; And needed opening and closing torque force is very little when the valve rod opening and closing, makes the opening and closing valve very fast and light.

The purpose of the utility model realizes through following technical proposal: the high pressure resistant valve stem packing ring of a kind of low friction; Its below is the filler seat ring; The top is a Gland, and integral body seals for ring-type is arranged between valve rod and the valve gap, comprises seal ring and preloading spring; Wherein seal ring simultaneously caves inward and forms an annular recess, and preloading spring is stuck in the annular recess and applies elastic force to the annular recess two side and impels the annular recess two side to exert pressure to valve rod and valve gap.

In such scheme, said seal ring is a laciniation with the position that valve rod contacts with valve gap.

In such scheme, leave certain flying height between said seal ring and the Gland.

Can find out from the structure characteristic of the utility model; The advantage of the utility model is: the utility model adopts preloading spring to combine with seal ring; No matter had muchly by pressure medium in the valve that sealed, sealed medium possibly produce leakage, desire to pass through the pressure stress of the contact position of valve rod and seal ring, will exceed an initial pressure stress all the time than sealed medium pressure; In other words: leakage is impossible produce, and sealing is effective.And seal ring has enough intensity and hardness, has guaranteed the stability at sealing position, utilizes laciniation, remains less sealing contact position, makes the opening and closing valve all very fast and light.

Description of drawings

The utility model will explain through embodiment and with reference to the mode of accompanying drawing, wherein:

Fig. 1 is the utility model mounting structure schematic representation;

Fig. 2 is the utility model ring structure schematic representation;

Fig. 3 is the utility model preloading spring structural representation;

Fig. 4 is that seal ring is connected schematic representation with preloading spring;

Reference character wherein: the 1st, valve rod 2 is that valve gap 3 is filler seat rings

The 4th, Gland 5 is that seal ring 6 is preloading springs

The 7th, annular recess 8 is that laciniation 9 is flying heights.

Embodiment

Below in conjunction with accompanying drawing the utility model is done further explanation.

Like Fig. 1-shown in Figure 4, after the utility model is in place, need compress and apply preload pressure with Gland, can give seal ring on the contrary and in stuffing box, stay certain flying height, with effective maintenance and excellent elasticity and the toughness of performance seal ring.Because the effect of preloading spring power; Produced an initial radial pressure distributed stress at seal ring and valve rod contact position; Because the structural design at the laciniation sealing position that the utility model is special; It is very narrow to make that seal ring and valve rod produce the position that effective contact stress seals, and promptly helps forming effective Sealing Stress and distributes, and helps the power of reducing friction greatly again.When no pressure existed in the valve, this initial radial pressure distributed stress can play the effective seal effect to medium in the valve, and when having pressure in the valve; Because the existence of initial pressure stress make pressure act on the preloading spring, and preloading spring acts on seal ring with this pressure; Finally act on and the contacted position of seal ring; Two kinds of pressure superposition that is to say, no matter pressure medium has much in the valve that is sealed; Sealed medium possibly produce leakage, desire to pass through the pressure stress of the contact position of valve rod and seal ring; All the time will exceed an initial pressure stress than sealed medium pressure, in other words: leakage is impossible produce, and sealing is effective.And simultaneously, seal ring adopts the special plastic alloy to process, and it is closely knit to have a material; Various media there is very strong anti-patience; The serviceability temperature scope is very wide; Under HTHP, promptly have enough intensity and hardness, have the pliability and the elasticity of fitting again with the sealing surface appropriateness; Friction factor is little, and wear resistance is good; Ozone resistance and ageing resistance are good, and long service life is because the enough intensity and the hardness of seal ring that sealing material is given; Guaranteed the stability of sealing contact position; Promptly remain few sealing contact position, add the minimum friction factor of material itself, needed opening and closing torque force is very little when making the valve rod opening and closing; Make the opening and closing valve very fast, very light.

Disclosed all characteristics in this specification except mutually exclusive characteristic, all can make up by any way.

Disclosed arbitrary characteristic in this specification (comprising any accessory claim, summary and accompanying drawing) is only if special narration all can be replaced by other equivalences or the alternative features with similar purpose.That is, only if special narration, each characteristic is an example in a series of equivalences or the similar characteristics.

The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection domain of the utility model.

Claims (3)

1. one kind is hanged down the high pressure resistant valve stem packing ring of friction; Integral body seals for ring-type is arranged between valve rod (1) and the valve gap (2); Its below is filler seat ring (3); The top is Gland (4); It is characterized in that comprising seal ring (5) and preloading spring (6), wherein seal ring (5) one side caves inward and forms an annular recess (7), and preloading spring (6) is stuck in the annular recess (7) and applies elastic force to annular recess (7) two side and impels annular recess (7) two side to exert pressure to valve rod (1) and valve gap (2).

2. the high pressure resistant valve stem packing ring of a kind of low friction according to claim 1 is characterized in that the position that said seal ring (5) and valve rod (1) contact with valve gap (2) is laciniation (8).

3. the high pressure resistant valve stem packing ring of a kind of low friction according to claim 1 is characterized in that leaving certain flying height (9) between said seal ring (5) and the Gland (4).

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