318. In some embodiments, the bottom thread 416 of thread 414 can be angled up at an angle θ_I1, which provides for more pressure between threads 414 and threads 318 that further enhances the seal between threads 318, especially bottom threads 322, and threads 414.

In a particular example of insulator 400 according to some embodiments, insulator 400 can have the following dimensions: L_I1=42.0 mm; L_I2=40.0 mm; L_I3=38.0 mm; L_I4=2.0 mm; W_I1=24.4 mm; W_I2=34.0 mm; D_I1=10.1 mm; θ_I1=118°; and Th_I1=DIN 405 RD 28×⅛. Insulator 400 is formed of an insulator, for example polyvinylidene fluoride (PVDF) plastic. This particular example is provided as an example only and is not intended to be limiting. Insulator 400 can have any dimensions that are consistent with integration with body 300.

FIGS. 4C through 4D illustrate a feedthrough 420 formed from the integration of insulator 400 with body 300. Feedthrough 420 can be used to provide access to the interior of a pressure vessel and can be used as feedthrough 104 as is described above with respect to FIG. 1. In operation, through-hole 412 is sized to accept a component 422. FIG. 4C illustrates insulator 400 integrated with body 300. Component 422 passes through through-hole 412 in insulator 400, extending through top portion 402 and through the bottom of feedthrough 420.

FIG. 4D illustrates a cross section along the length of feedthrough 420 as illustrated in FIG. 4C. FIG. 4C further illustrates threads 414 of insulator 400 engaged with threads 318 of body 300. As is illustrated, tooth 416 of threads 414, which is one of the lower teeth of threads 414, serves to apply pressure on the tapered part threads 318, lower portion 322, to provide for a better seal, in addition to the seal formed by the threads themselves. As is further illustrated, pressure P can be applied to compress and plastically deform barrel portion 304, thereby further providing compressing and deforming barrel portion 404 of insulator and establishing a seal between barrel portion 404 and component 422.

FIGS. 5A and 5B illustrates another embodiment of an insulator, insulator 500, that is compatible with body 300 as illustrated in FIGS. 3A and 3B. As is illustrated in FIGS. 5A and 5B, the example insulator 500 is compatible with a component passing through a through-hole 512 in insulator 500. Through-hole 512 can be centered in insulator 500 or may be offset from center. Insulator 500 also includes a fill tube structure 540 formed by pipes 522 and 532 coupled to a fill through-hole 524, as discussed further below.

As illustrated in FIG. 5A, insulator 500 can have a length of L_I5 and includes a top portion 502 and a barrel portion 504. Barrel portion 504 includes a bottom section 506, a central section 508, and a top section 510. Threads 514 are formed on the outer surface of central section 508. As is illustrated in FIG. 5A, bottom section 506 has a length along barrel 504 of L_I8. Center section 508 extends from bottom section 506 to a length of L_I7 (measured from the end of bottom section 506). Top section 510 extends from the end of center section 508 to a length of L_I6 (measured from the bottom of bottom section 506). Barrel portion 504 has an outer diameter W_I3 on which threads 514 are formed. Top portion 502 extends from the top of top section 510 to length L_I5 of insulator 500. FIG. 5B illustrates a view from bottom section 506 further illustrating through-hole 512 formed in center section 508 of insulator 500. As is illustrated in FIG. 5B, through-hole 512 has a diameter of D_I2 and is centered in barrel portion 404. In some embodiments, through-hole 512 may be offset in center section 508. Further, as shown in FIG. 5B, top section 510 of barrel portion 504 has a diameter of W_I4.

In operation, insulator 500 is screwed into body 300 to form a feedthrough 546 as illustrated in FIG. 5C. Consequently, threads 514 of insulator 500 engage with threads 318 of body 300. As such, in some embodiments, where teeth 320 of threads 318 are round or square, then teeth 518 of threads 514 are also rounded or square to match. In some embodiments, the bottom threads 322 of body 300 are tapered. In addition, in some embodiments, the bottom thread 516 of thread 514 can be angled up at an angle ea as is illustrated in FIG. 5A, which provides for more pressure between threads 514 and threads 318 that further enhances the seal between threads 318 and threads 514.

As is further illustrated in FIGS. 5A and 5B, insulator 500 includes a structure 540 that allows further access to the interior of a pressure vessel additional to through-hole 512. The example of structure 540 illustrated in FIGS. 5A and 5B facilitates a filling structure for addition and/or removal of gasses and/or liquids into/from the pressure vessel to which body 300 is attached. For example, in a hydrogen-metal battery electrolyte and gasses such as hydrogen gas may be added to the pressure vessel or the pressure vessel may be evacuated through structure 540.

As illustrated in FIG. 5A, a separate through-hole 524 is formed through insulator 500 and is attached to a first pipe 532 and a second pipe 522 that extend from top portion 502. First pipe 532 and second pipe 522 are integrally formed as part of insulator 500. First pipe 532 has a through-hole of 530 and second pipe 522 has a through hole of 526, which are joined with through-hole 524. As is illustrated in FIG. 5A, pipe 532 has an inner diameter DI6, an outer diameter DI5, forming through-hole 530, and a length of L_I9. Pipe 532 extends perpendicularly from top portion 502 such that through-hole 530 aligns with through-hole 524. Pipe 522 has an inner diameter D_I4 and outer diameter D_I3 that forms through-hole 526. Pipe 522 is angled an angle θ_I3 from the surface of top portion 502 and is positioned such that through-hole 526 is coupled with through-hole 524. Further, pipe 522 may be formed above top portion 502.

Through-hole 530 may include a barrier 528 at a position that blocks through-hole 530 but allows access to through-hole 524 by through-hole 526 of pipe 522. In operation, once the pressure vessel has been charged through pipe 522, a plug may be inserted through through-hole 530 (breaking blockage 528) and into through-hole 524. As illustrated in FIG. 5A, barrier 528 can be a thin layer of thickness L_I10. When body 300, into which insulator 500 is incorporated, is compressed and plastically deformed a seal is formed between the plug and through-hole 524 as well as forming a seal between the walls of through-hole 512 and a component that is inserted through through-hole 512.

FIG. 5B illustrates a top view of insulator 500, which illustrates structure 540 having pipe 522 and pipe 532. Further, threads 514, top portion 502, and through-hole 512 is illustrated.

A specific example of insulator 500 can have the following dimensions: LI5=42.0 mm; LI6=40.0 mm; LI7=38.0 mm; LI8=2.0 mm; LI9=16.0 mm; LI10=0.5 mm; WI3=24.4 mm; WI4=34.0 mm; DI2=10.1 mm; DI3=6.0 mm; DI4=4.0 mm; DI5=6.0 mm; DI6=4.0 mm; θI2=118°; θI3=60°; and ThI2=DIN 405 RD 28×⅛. Insulator 500 may be formed of an insulating material, for example polyvinylidene fluoride (PVDF) plastic. This particular example is provided as an example only and is not intended to be limiting. Insulator 500 can have any dimensions that are consistent with integration with body 300.

FIGS. 5C and 5D illustrate a feedthrough 546 according to some embodiments of the present disclosure. Feedthrough 546 can be used as feedthrough 104 in FIG. 1. FIG. 5D illustrates a cross-sectional view of feedthrough 546 as illustrated in FIG. 5C. FIG. 5C illustrates feedthrough 546 that includes insulator 500 incorporated with body 300. FIG. 5C illustrates component 542 extending through through-hole 512 in insulator 500. Further, FIG. 5C illustrates structure 540 that includes pipes 522 and 532. As discussed above, body 300 is mounted to a pressure vessel wall at base 302.

FIG. 5D illustrates a cross sectional view of feedthrough 546. As illustrated in FIG. 5D, a plug 544 can be positioned to be inserted through pipe 532 into through-hole 524. Plug 544 can be formed of a rigid rod, for example a metallic rod, sized appropriately to seal within through-hole 524. Threads 318 of body 300 are engaged with threads 514 of insulator 500. As illustrated, bottom threads 516 are tapered as indicated above to help form a seal between threads 318 of body 300 and threads 514 of insulator 500. In some embodiments, through-hole 512 can be sized such that a tight fit can be formed with component 542 to form an interference fit that forms a weak seal. Further, FIG. 5D illustrates the placement of press 550 that can apply pressure to compress and plastically deform barrel 304 of body 300 to finalize the seals between threads 318 of body 300 and threads 514 of insulator 500 as well as seals between insulator 500 and plug 544 and component 542.

FIGS. 6A through 6G illustrates assembly and use method 600 of feedthrough 546 as described above with respect to FIGS. 5C and 5D above. Method 600 starts with step 602, where insulator 500 is screwed into body 300. As discussed above, body 300 has been attached to the wall of a pressure vessel by base 302. As is discussed above, with tapered threads 322 of body 300 and threads 516 of insulator 500, threads 318 of body 300 and threads 514 of insulator 500 form a seal as is illustrated in FIG. 6B, which illustrates threads 514 engaged with threads 318.

In step 604, component 542 is inserted through through-hole 512. FIG. 6B illustrates performance of steps 602 and 604. As discussed above, an interference fit is formed between component 542 and insulator 500 within through-hole 512. Further, tapered threads 322 in combination with angled threads 516 help create a seal between insulator 500 and body 300 at threads 318 and threads 514 as discussed above.

Once the seals between threads 318 and threads 514 is formed and the interference seal between component 542 and insulator 500 in through-hole 512 is formed in steps 602 and 604, method 600 proceeds to step 606 where structure 500 is used as needed according to the use of the pressure vessel that feedthrough 546 is attached. As is discussed, pipe 522 can be used to add or remove liquid or gas while pipe 532 is sealed by barrier 528. Consequently 522 can be used to pressurize the pressure vessel, or used to pull a vacuum on the pressure vessel, as is illustrated in FIG. 6C. In the example where pressure vessel is a hydrogen-metal battery, pipe 522 can be used to first pull a vacuum on the pressure vessel, then add electrolyte to the pressure vessel, then drain any excess electrolyte from the pressure vessel. Further, if needed, gasses such as hydrogen or an inert gas can be added to the pressure vessel.

Once the appropriate conditions (i.e. addition of liquid and/or gas or evacuation) have been achieved using pipe 522, then method 600 proceeds to step 608. In step 608, as is illustrated in FIG. 6D, plug 544 is pushed through blockage 528 into through-hole 524. In step 610, as is illustrated in FIG. 6E, press 550 is used to compress and plastically deform barrel 304 of body 300 such that threads 318 are compressed and plastically deformed against threads 514, through-hole 512 is compressed and plastically deformed against component 542, and through hole 524 is compressed and plastically deformed against plug 544 to create strong seals against whatever pressure is in the pressure vessel to which feedthrough 546 is attached. Method 600 then proceeds to step 612.

In step 612, pipes 522 and 532 of structure 540 can be removed from insulator