PRESSURE CONTAINER

Abstract

A pressure vessel capable of improving reliability as the temperature decreases comprises a gas containment section (110), a valve, a sealing element, and a metallic, tubular element (140). The gas containment section (110) has a resin lining (111) and a fiber-reinforced resin layer (112) covering the outer surface of the lining (111), with a neck (114) having an opening (113) at its apex. The valve has an insertion section that is inserted through the opening (113) into the neck (114), forming a gas flow channel that allows the interior of the gas containment section (110) and an external space to communicate with each other. The sealing element seals a space between the neck (114) and the insertion section.The tubular element (140) is arranged in the neck (114) between the lining (111) and the fiber-reinforced resin layer (112) and around the sealing element and has anchor sections (143) and (144) embedded in the lining (111), with the inner and outer surfaces (141, 142) being covered with the synthetic resin material of the lining (111).

Description

BACKGROUND Technical field The present invention relates to a pressure vessel. State of the art A gas tank for filling with a high-pressure gas such as hydrogen is already known. JP 2009-174 700 A discloses a gas tank comprising a lining to which a cap element is attached and a fiber-reinforced layer formed by layering fibers on the outer circumference of the lining using the precision winding method. The inner layer portion of the fiber-reinforced layer of this conventional gas tank is provided with an air-permeable layer containing fine cavities formed between the fibers (see abstract, claim 1, paragraph 0007 and Fig. 3 of JP 2009-174 700 A). According to this conventional gas tank design, the gas, which penetrates the lining under high pressure, is gradually released through the air-permeable layer with its cavities formed between the fibers that make up the fiber-reinforced layer, via a gap between the lining and the cap element, without stagnating in a section between the lining and the fiber-reinforced layer. In contrast to a case where grooves are formed in the fiber-reinforced layer, this reduces the disadvantage of the rapid escape of highly concentrated gas that would otherwise stagnate in a section between the lining and the fiber-reinforced layer, while ensuring sufficient strength.Furthermore, if the internal pressure of the gas tank decreases, inward deformation of the lining due to the high-pressure gas between the lining and the fiber-reinforced layer can also be reduced (see paragraph 0008 of JP 2009-174 700 A). In this conventional gas tank, the mouth section of the liner has an inwardly extending portion and a cylindrical fitting portion, with the inner side of the fitting portion acting as the mouth section. The inwardly extending portion extends from the inner edge of the liner shoulder at an angle to the central axis such that its smaller-diameter section is positioned inward from the liner. The cylindrical fitting portion projects into the liner from the side of the inwardly extending portion opposite the shoulder, along the axial direction of the liner. An insert ring is integrally formed on the outer circumference of the fitting portion.The insert ring tightens an O-ring which is fitted between the fitting section and an adjacent section of the cap element to be pressed into the fitting section (see paragraphs 0028 and 0029 and Fig. 2 of JP 2009 - 174 700 A). WO 2013 / 080 810 A1 discloses a pressure vessel with the features of the preamble of claims 1 and 3. This pressure vessel has a metallic reinforcing element embedded in a lining between an O-ring and a metallic mouthpiece. SUMMARY As described above, in the aforementioned conventional gas tank, the insert ring is designed on the outer circumference of the cylindrical fitting section, which is part of the mouth section of the liner, such that it is integrally formed with the liner and tightens the O-ring fitted between the liner's fitting section and the adjacent section of the cap element. With such a design, as the gas tank's temperature decreases, both the resin liner and the metallic insert ring shrink. Due to the difference in the coefficient of thermal expansion between the liner and the insert ring, this shrinkage creates stress that could cause the liner to separate from the insert ring, potentially impairing the gas tank's reliability. The present invention provides a pressure vessel that is capable of improving reliability when the temperature decreases. One embodiment of the present invention is a pressure vessel having the features of claim 1. According to a further embodiment of the present invention, a pressure vessel has the features of claim 3. Claims 2 and 4 each deal with further developments of these embodiments. According to the above-mentioned embodiments of the present invention, a pressure vessel can be provided which is capable of improving reliability when the temperature decreases. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view showing embodiment 1 of a pressure vessel according to the present invention; Fig. 2 is an enlarged sectional view of a neck of a gas containment section of the pressure vessel shown in Fig. 1; Fig. 3 is a sectional view illustrating a method for manufacturing a lining of the gas containment section shown in Fig. 2; Fig. 4 is an enlarged sectional view of embodiment 2 of the pressure vessel of the present invention, the view corresponding to that of Fig. 2; and Fig. 5 is a sectional view illustrating a method for manufacturing the lining of the gas containment section shown in Fig. 4. DETAILED DESCRIPTION With reference to the drawings, exemplary embodiments of a pressure vessel according to the present invention are described below. - Example 1 - Fig. 1 is a sectional view showing embodiment 1 of a pressure vessel according to the present invention. A pressure vessel 100 of this embodiment is, for example, a tank to be mounted on a fuel cell vehicle or a hydrogen vehicle and to be filled with high-pressure hydrogen gas. The pressure vessel 100 has, for example, a gas containment section 110, a valve 120, a sealing element 130, and a tubular element 140. Furthermore, the pressure vessel 100, shown in Fig. 1 as an example, has a valve holder 150 for attaching the valve to the gas containment section 110. The gas containment section 110 has a synthetic resin lining 111 and a fiber-reinforced resin layer 112 covering the outer surface of the lining 111. Furthermore, the gas containment section 110 is provided with a neck 114 having an opening 113 at its apex. More precisely, the gas containment section 110 has a cylindrical neck 114, a shoulder 115 connected to the neck 114 and having a larger diameter than the neck 114, a cylindrical body 116 connected to the shoulder 115, and a domed or hemispherical end 117 connected to the body 116. The shoulder 115 is domed or hemispherical with a diameter that, for example, gradually increases in a gentle curve from the neck 114 to the body 116. The liner 111 is a resin inner container with gas barrier properties, defining an interior space IS for housing gas. Examples of materials that can be used for the liner 111 include polyamide, polyethylene, ethylene-vinyl alcohol copolymer (EVOH), polyester, and epoxy. For example, if polyamide 6 is used as the material for the liner 111, the coefficient of linear expansion of the liner 111 is approximately 13 × 10⁻⁵ K⁻¹. The fiber-reinforced resin layer 112 acts as a reinforcing layer to ensure the strength of the gas containment section 110 by covering the outer surface of the liner 111 that contains the gas. The fiber-reinforced resin layer 112 is provided by wrapping a fiber bundle impregnated with an uncured resin around the liner 111, and curing the resin with which the fiber bundle is impregnated to cover the outer surface of the liner 111. Examples of fiber bundle materials for the fiber-reinforced resin layer 112 that can be used include glass fibers, aramid fibers, boron fibers, and carbon fibers. It should be noted that, for reasons of low weight and mechanical strength, carbon fibers are sometimes used as the fiber bundle material for the fiber-reinforced resin layer 112. Examples of resins that can be used to impregnate the fiber bundle of the fiber-reinforced resin layer 112 include thermoplastic resins such as polyetheretherketone, polyphenylene sulfide, polyacrylate, polyimide, or polyamide. Furthermore, examples of resins that can be used to impregnate the fiber bundle of the fiber-reinforced resin layer 112 also include thermosetting resins such as phenolic resins, melamine resins, urea resins, or epoxy resins. The valve holder 150, for example, is a cylindrical, metallic element that is to be attached to the outside of the cylindrical neck 114 of the gas containment section 110. The valve holder 150 is attached to the outside of the neck 114 such that a projection of a holder, provided on the inner circumferential surface, engages in the outer circumferential surface of the neck 114. The outer circumferential surface of the valve holder 150 is threaded for securing the valve 120. The valve 120 is a metallic element comprising, for example, a cylindrical insertion section 121, which is to be inserted into the neck 114 through the opening 113 of the gas housing section 110, and a gas flow channel 122, which is provided in the insertion section 121 and allows the interior IS of the gas housing section 110 and an exterior OS to communicate with each other. Furthermore, the valve 120 has, for example, a recessed mounting section 123, which is to be attached to a pointed end section of the neck 114 of the gas housing section 110. The mounting section 123 is attached to the tip end of the cylindrical neck 114 of the gas housing section 110 via the valve holder 150, wherein a thread provided on its inner circumferential surface, which faces the outer circumferential surface of the valve holder 150, is screwed onto the thread on the outer circumferential surface of the valve holder 150. The insertion section 121 of the valve 120 is inserted into the interior of the lining 111 of the cylindrical neck 114 of the gas containment section 110 when the thread of the mounting section 123 is screwed onto the thread of the valve holder 150. The insertion section 121 has the gas flow channel 122, which allows the interior IS of the gas containment section 110 and the exterior OS to communicate with each other. The sealing element 130 seals a space between the neck 114 of the gas containment section 110 and the insertion section 121 of the valve 120. More precisely, the sealing element 130 is, for example, an O-ring that is arranged between the outer circumferential surface of the insertion section 121 and the lining 111 of the neck 114 and hermetically seals the space between the neck 114 of the gas containment section 110 and the insertion section 121 of the valve 120. The sealing element 130 is, for example, arranged in a recessed groove formed on the outer circumferential surface of the insertion section 121 of the valve 120. The tubular element 140 is a metallic, tubular or annular element arranged in the neck 114 of the gas containment compartment 110 between the lining 111 and the fiber-reinforced resin layer 112, and around the sealing element 130. The tubular element 140 is also referred to as an insert ring. The tubular element 140 is designed, for example, to prevent a deterioration of the sealing properties of the sealing element 130 due to the expansion of the fiber-reinforced resin layer 112 when the interior IS of the gas containment compartment 110 is filled with gas, thereby increasing the internal pressure of the gas containment compartment 110. The coefficient of linear expansion of the metallic, tubular element 140 is smaller than that of the resin lining 111. The material of the tubular element 140 is not particularly restricted; for example, stainless steel can be used. If stainless steel (SUS316L) is used as the material of the tubular element 140, its coefficient of linear expansion is approximately 1.6 × 10⁻⁵ K⁻¹, which is one-eighth or less than that of the lining 111. Therefore, when the temperature of the pressure vessel 100 decreases, the lining 111 shrinks more than the tubular element 140. Fig. 2 is an enlarged sectional view of the neck 114 of the gas containment section 110 of the pressure vessel 100 shown in Fig. 1. The tubular element 140 has anchor sections 143 and 144 embedded in the lining 111, with an inner surface 141 and an outer surface 142 covered with the resin material of the lining 111. It should be noted that the tubular element 140 can have only one of the two anchor sections 143 and 144. The anchor sections 143 and 144 can be provided, for example, wholly or partially, in the circumferential direction of the tubular element 140. A first anchor section 143 is provided in the direction of a central axis CA of the tubular element 140 in the tip end section of the tubular element 140, the tip end section being positioned at the tip of the neck 114 close to the opening 113. Furthermore, a second anchor section 144 is provided in the direction of the central axis CA of the tubular element 140 in a near end section of the tubular element 140, which extends from a near end section of the neck 114 towards a tip end section of the shoulder 115 of the gas containment section 110. In the example shown in Fig. 2, the lining 111 in the tip section of the neck 114 has a section of enlarged diameter 111a, the outer diameter of which is also enlarged. The section of enlarged diameter 111a extends, for example, from the opening 113 at the tip of the neck 114 towards the tip section of the tubular element 140, where the anchor section 143 is formed in the direction of the central axis CA. It should be noted that the central axis CA of the neck 114 and the annular element 140 corresponds, for example, to the central axis CA of the gas containment section 110. In the example shown in Fig. 2, the lining 111 is thicker in the section with the increased diameter 111a than in the other sections. The first anchor section 143 is embedded in the section with the increased diameter 111a of the lining 111, the diameter increasing with decreasing distance from the tip of the neck 114. The inner surface 141 and the outer surface 142 of the first anchor section 143 are covered with the resin material of the lining 111. Specifically, in the example shown in Fig. 2, a thin layer of the resin material of the lining 111 is formed between the outer surface 142 of the first anchor section 143 and the fiber-reinforced resin layer 112. Furthermore, the lining 111 in the tip end section of the shoulder 115, which is connected to the near end section of the neck 114, has, for example, a thick section 111b, which, like the enlarged diameter section 111a, is thicker than the other sections. The second anchor section 144 is embedded in the thick section 111b of the lining 111, which is provided in the shoulder 115 of the gas containment section 110, the diameter of which increases with increasing distance from the neck 114. The inclination angle α of the outer surface 142 of the second anchor section 144 with respect to the central axis CA of the neck 114 is smaller than the inclination angle β of the outer surface of the thick section 111b of the lining 111 with respect to the central axis CA of the neck 114. The outer surface 142 of the anchor section 144 is therefore covered with the synthetic resin material of the lining 111, so that a layer consisting of the synthetic resin material of the lining 111 is formed between the anchor section 144 and the fiber-reinforced resin layer 112. Fig. 3 is a sectional view illustrating a method for manufacturing the lining 111 of the gas containment section 110 shown in Fig. 2. The lining 111 is formed such that several sections of the gas containment section 110 are formed separately in the direction of the central axis CA, and the formed sections are joined together by welding or the like, so that they are formed in one piece. A method for manufacturing the end section of the lining 111 is described here, which forms the neck 114, the shoulder 115, and part of the body 116 of the gas containment section 110. First, the tubular element 140 is attached to a die D for the lining 111. At this point, a gap G is formed between the inner wall surface of the die D and the outer surface 142 of the anchor sections 143 and 144 of the tubular element 140. The outer surface 142 of a straight tube section 145 between the anchor sections 143 and 144 of the tubular element 140 is positioned tightly against the inner wall surface of the die D. In this state, injection molding takes place by injecting molten resin material of the lining 111 through a gate D1 of the die D, causing it to flow in the direction indicated by the arrows. During injection molding, the molten resin material of the lining 111 enters the gap G between the inner wall surface of the die D and the inner wall surface 141 of the anchor sections 143 and 144 of the tubular element 140, so that the inner wall surface 141 and the outer surface 142 of the anchor sections 143 and 144 are covered with the resin material of the lining 111. In this way, the lining 111 and the tubular element 140 are formed in one piece by overmolding. The outer surface 142 of the straight tube section 145 of the tubular element 140, which is positioned close to the inner wall surface of the die D, is exposed by the lining 111 without being covered with the resin material of the lining 111, so that it contacts the fiber-reinforced resin layer 112. It should be noted that the gap G can be formed between the outer surface 142 of the straight pipe section 145, located between the anchor sections 143 and 144 of the tubular element 140, and the inner wall surface of the die D. In this case, the inner surface 141 and the outer surface 142 of the straight pipe section 145 of the tubular element 140, as well as the inner surface 141 and the outer surface 142 of the anchor sections 143 and 144, are covered with the resin material of the lining 111. That is, the tubular element 140 is completely embedded in the resin material of the lining 111, with its outer surface being completely covered by the resin material of the lining 111. The effects of pressure vessel 100 of this embodiment are described below in comparison with the conventional gas tank mentioned above. In the conventional gas tank mentioned above, as described above, the insert ring is provided on the outer circumference of the cylindrical fitting section, which is part of the mouth section of the liner, so that it is formed integrally with the liner. It tightens the O-ring that is fitted between the fitting section of the liner and the adjacent section of the cap element. With such a design, when the temperature of the gas tank decreases, both the resin liner and the metallic insert ring shrink. Due to the difference in the coefficient of thermal expansion between the liner and the insert ring, this shrinkage causes stress that can cause the liner to separate from the insert ring, potentially impairing the reliability of the gas tank. In contrast, the pressure vessel 100 of this embodiment comprises the gas containment section 110, the valve 120, the sealing element 130, and the metallic, tubular element 140. The gas containment section 110 has the synthetic resin lining 111 and the fiber-reinforced resin layer 112, which covers the outer surface of the lining 111. The gas containment section 110 is provided with the neck 114, which has the opening 113 at its apex. The valve 120 comprises the insertion section 121, which is to be inserted into the neck 114 through the opening 113, and the gas flow channel 122, which is provided in the insertion section 121 and allows the interior IS of the gas containment section 110 and the exterior OS to communicate with each other. The sealing element 130 seals a space between the neck 114 and the insertion section 121.The tubular element 140 is arranged in the neck 114 between the lining 111 and the fiber-reinforced resin layer 112 and around the sealing element 130. Furthermore, the tubular element 140 has the anchor sections 143 and 144, which are embedded in the lining 111, with the inner surface 141 and the outer surface 142 being covered with the resin material of the lining 111. Such a configuration enables the pressure vessel 100 of this embodiment, with the tubular element 140 arranged on the inside of the fiber-reinforced resin layer 112 around the sealing element 130, to suppress the deterioration of the sealing property of the sealing element 130 due to the expansion of the fiber-reinforced resin layer 112 when the internal pressure of the gas containment section 110 increases. Furthermore, the anchor sections 143 and 144 of the tubular element 140 are embedded in the lining 111, with the inner surface 141 and the outer surface 142 of the anchor sections 143 and 144 being covered with the resin material of the lining 111.Therefore, when the temperature of the pressure vessel 100 decreases, the lining 111 is retained by the tubular element 140 with anchor sections 143 and 144, even if the lining 111 shrinks more than the tubular element 140, thus preventing the lining 111 from being removed from the tubular element 140. This can improve the reliability of the pressure vessel 100 when the temperature decreases. Furthermore, the lining 111 in the pressure vessel 100 of this embodiment has a section of enlarged diameter 111a with an enlarged outer diameter in the tip end section of the neck 114. Additionally, the anchor section 143 of the tubular element 140 is embedded in the section of enlarged diameter 111a of the lining 111, the diameter of which increases with decreasing distance from the tip of the neck 114. Such a configuration allows the pressure vessel 100 of this embodiment to have enlarged areas of the inner surface 141 and the outer surface 142 of the anchor section 143, which are covered with the resin material of the lining 111, in order to firmly hold the lining 111 in place with the anchor section 143. Furthermore, the anchor section 143, with its enlarged diameter at the tip end of the neck 114, also securely holds the lining 111 in place, thus preventing its removal, even when stress is exerted by the tubular element 140 in the direction of the central axis CA of the tubular element 140, due to the difference in the coefficient of linear expansion between the lining 111 and the tubular element 140. Furthermore, the gas containment section 110 in the pressure vessel 100 of this embodiment has a shoulder 115, which is connected to the near end section of the neck 114 and has a diameter that is larger than that of the neck 114. The anchor section 144 of the tubular element 140 is embedded in the lining 111 of the shoulder 115, with its diameter increasing with increasing distance from the neck 114. In addition, the angle of inclination α of the outer surface 142 of the anchor section 144 with respect to the central axis CA of the neck 114 is smaller than the angle of inclination β of the outer surface of the lining 111 of the shoulder 115 with respect to the central axis CA. Such a configuration allows the pressure vessel 100 of this embodiment to have enlarged areas of the inner surface 141 and the outer surface 142 of the anchor section 144, which are covered with the resin material of the lining 111, thereby firmly holding the lining 111 in place with the anchor section 144. Furthermore, the anchor section 144, with its diameter increasing with increasing distance from the neck 114, also securely holds the lining 111 in place, thus preventing its removal when stress is exerted due to the difference in the coefficient of linear expansion between the lining 111 and the tubular element 140 in the direction of the central axis CA of the tubular element 140. Furthermore, the inclination angle α of the outer surface 142 of the anchor section 144 with respect to the central axis CA of the neck 114 is smaller than the inclination angle β of the outer surface of the lining 111 of the shoulder 115 with respect to the central axis CA. Therefore, the resin material of the lining 111, which covers the outer surface 142 of the anchor section 144, becomes thicker with increasing distance from the neck 114, so that the anchor section 144 can hold the lining 111 more firmly. As described above, this embodiment can provide the pressure vessel 100 which is able to improve reliability when the temperature decreases by retaining the lining 111 with the anchor sections 143 and 144 of the tubular element 140. - Example 2 - Next, with reference to Fig. 1, which shows embodiment 1, and to Figs. 4 and 5, embodiment 2 of the pressure vessel according to the present invention will be described. Fig. 4 is an enlarged sectional view of embodiment 2 of the pressure vessel according to the present invention, the view corresponding to the view in Fig. 2, which shows embodiment 1. Fig. 5 is a sectional view to illustrate a method for manufacturing the lining 111 of the gas containment section 110 shown in Fig. 4. In the pressure vessel 100 of this embodiment, the anchor sections 146 and 147 of the tubular element 140 are configured differently from the anchor sections of the aforementioned pressure vessel 100 of embodiment 1. Since the remaining sections of the pressure vessel 100 of this embodiment are configured in the same way as in the aforementioned pressure vessel 100 of embodiment 1, the corresponding parts are designated with the same reference numerals and their description is omitted. In the pressure vessel 100 of this embodiment, the lining 111 has, in the tip end section of the neck 114, the section of enlarged diameter 111a with the enlarged outer diameter, as in the aforementioned pressure vessel 100 of embodiment 1. Furthermore, in the pressure vessel 100 of this embodiment, a first anchor section 146 of the tubular element 140 is embedded in the section of enlarged diameter 111a of the lining 111 and has a through-hole 148 that extends radially through the tubular element 140. As shown in Fig. 5, in this configuration, the inner surface 141 and the outer surface 142 of the anchor section 146 are covered with the resin material when the molten resin material of the lining 111 is injected through the gate D1 of the die D to overmold the tubular element 140 in the lining 111. Furthermore, the through-hole 148 is filled with the molten resin material. The lining 111 can thus be firmly attached to the anchor section 146 of the tubular element 140 after molding. Furthermore, in the pressure vessel 100 of this embodiment, a second anchor section 147 is embedded in the lining 111 of the shoulder 115 of the gas containment section 110, as in the aforementioned pressure vessel 100 of embodiment 1. In addition, the second anchor section 147 in the gas containment section 110 of this embodiment has an inclined surface 149 that forms an acute angle with the inner surface 141 and an obtuse angle with the outer surface 142. Moreover, the inner surface 141 and the inclined surface 149 in the anchor section 147 are covered with the synthetic resin material of the lining 111. As shown in Fig. 5, in such a configuration, the inclined surface 149 on the outside of the anchor section 147 is covered with the resin material coming from the side of the inner surface 141 when the molten resin material of the lining 111 is injected through the gate D1 of the die D to overmold the tubular element 140 in the lining 111. This causes the anchor section 147 to dig into the resin material of the lining 111, as shown in Fig. 4, so that the resin material of the lining 111 lies on the outside of the anchor section 147. Thus, after molding, the lining 111 can be firmly attached to the anchor section 147 of the tubular element 140. Accordingly, this embodiment, like the aforementioned embodiment 1, can provide the pressure vessel 100, which is able to improve reliability when the temperature decreases by retaining the lining with the anchor sections 146 and 147 of the tubular element 140. Although detailed embodiments of the pressure vessel according to the present invention have been described with reference to the drawings, the specific configuration is not limited thereto, and any design changes are possible within the scope of protection of the patent claims. REFERENCE MARK LIST 100 Pressure vessel 110 Gas containment section 111 Lining 111a Enlarged diameter section 112 Fiber-reinforced resin layer 113 Opening 114 Neck 115 Shoulder 120 Valve 121 Insertion section 122 Gas flow channel 130 Sealing element 140 Tubular element 141 Inner surface 142 Outer surface 143 Anchor section 144 Anchor section 146 Anchor section 147 Anchor section 148 Through hole 149 Inclined surface CA Central axis IS Interior OS Exterior α Angle of inclination β Angle of inclination

Claims

A pressure vessel (100) comprising: a gas containment section (110) having a resin lining (111) and a fiber-reinforced resin layer (112) covering an outer surface of the lining (111), the gas containment section (110) being provided with a neck (114) having an opening (113) at one end; a valve (120) having an insertion section (121) to be inserted into the neck (114) through the opening (113) and a gas flow channel (122) provided in the insertion section (121), the gas flow channel (122) allowing an interior (IS) of the gas containment section (110) and an exterior (OS) to communicate with each other; a sealing element (130) adapted to seal a space between the neck (114) and the insertion section (121) to seal;and a metallic, tubular element (140) arranged in the neck (114) around the sealing element and having an anchor section (143, 144) embedded in the lining (111), wherein an inner surface (141) and an outer surface (142) of the anchor section (143, 144) are covered with a synthetic resin material of the lining (111), characterized in that the tubular element (140) is arranged between the lining (111) and the fiber-reinforced resin layer (112), the lining (111) has in a tip end section of the neck (114) a section of enlarged diameter (111a) with an enlarged outer diameter, and the anchor section (143) is embedded in the section of enlarged diameter (111a) of the lining (111), wherein a diameter increases with decreasing distance from the tip of the neck (114). Pressure vessel (100) according to claim 1, wherein the gas containment section (110) has a shoulder (115) which is connected to a near end section of the neck (114) and which has an increased diameter compared to the neck (114), the anchor section (144) is embedded in the lining (111) of the shoulder (115), wherein the diameter of the anchor section (144) increases with increasing distance from the neck (114), and an inclination angle (α) of the outer surface (142) of the anchor section (144) with respect to a central axis (CA) of the neck (114) is smaller than an inclination angle (β) of the outer surface of the lining (111) of the shoulder (115) with respect to the central axis (CA). A pressure vessel (100) comprising: a gas containment section (110) having a resin lining (111) and a fiber-reinforced resin layer (112) covering an outer surface of the lining (111), the gas containment section (110) being provided with a neck (114) having an opening (113) at one end; a valve (120) having an insertion section (121) to be inserted into the neck (114) through the opening (113) and a gas flow channel (122) provided in the insertion section (121), the gas flow channel (122) allowing an interior (IS) of the gas containment section (110) and an exterior (OS) to communicate with each other; a sealing element (130) adapted to seal a space between the neck (114) and the insertion section (121) to seal;and a metallic, tubular element (140) arranged in the neck (114) around the sealing element and having an anchor section (146, 147) embedded in the lining (111), wherein an inner surface (141) and an outer surface (142) of the anchor section (146, 147) are covered with a synthetic resin material of the lining (111), characterized in that the tubular element (140) is arranged between the lining (111) and the fiber-reinforced resin layer (112), the lining (111) has in a tip end section of the neck (114) a section of enlarged diameter (111a) with an enlarged outer diameter, and the anchor section (146) is embedded in the section of enlarged diameter (111a) of the lining (111) and has a through-hole (148) extending radially through the tubular element (140) extends.; Pressure vessel (100) according to claim 3, wherein the anchor section (147) has an inclined surface (149) which forms an acute angle with the inner surface (141) of the anchor section (147) and an obtuse angle with the outer surface (142) of the anchor section (147), wherein the inner surface (141) and the inclined surface (149) are covered with the synthetic resin material of the lining (111).

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