100 on the pipe 500, thereby sealing the pipe 500 to the cap 112. In other aspects, the pipe fitting 110 can be another type of pipe fitting such as a tee, an elbow, a reducer, a valve, or any other suitable type of pipe fitting.

As shown and further described with respect to FIGS. 5, 6A, and 6B, the cap 112 can interfere with the gasket 140 so that the coupling 170 can be retained on the cap 112 when the coupling 170 is in the relaxed position. It can be desirable for the coupling 170 to be retained on the cap 112 so that the pre-assembled coupling assembly 100 can be easily attached to the pipe 500. For example, a user can hold the pipe 500 with one hand, and the pre-assembled coupling assembly 100 can be slipped over the end 502 of the pipe 500 with a second hand of the user. Additionally, because the coupling 170 can be retained on the pipe fitting 110, the user is less likely to lose or mix up parts, such as in a field environment, because the pre-assembled coupling assembly 100 may not come apart without a deliberate effort by the user.

FIG. 2 is a perspective view of another aspect of the pre-assembled coupling assembly 100 comprising the coupling 170 of FIG. 1 and another aspect of the pipe fitting 110 in accordance with another aspect of the present disclosure. In the present aspect, the pipe fitting 110 can be a drain cap 212. The drain cap 212 can be similar to the cap 112 of FIG. 1; however, the drain cap 212 can define a drain bore 214 extending through the drain cap 212. In the present aspect, the drain bore 214 can define internal threading 216, for example and without limitation, National Pipe Thread (“NPT”) tapered threading. The internal threading 216 can be configured to receive a plug or a drain pipe which can define external threading shaped complimentary to the internal threading 216. In other aspects, the drain cap 212 can be used for purposes other than draining. For example and without limitation, an instrument, such as a pressure gauge for example and without limitation, can be attached to the drain bore 214 so that properties of fluids within the piping system can be monitored. In other aspects, a small valve can be attached to the drain bore 214, for example and without limitation, which can be used for sampling fluids or injecting fluids into the piping system.

FIG. 3 is a front view of the pre-assembled coupling assembly 100 of FIG. 1. FIG. 4 is a front view of the pre-assembled coupling assembly 100 of FIG. 2. Angles and dimensions shown in FIGS. 1-16C are merely exemplary and should not be viewed as limiting. The structures and components shown can be scaled upwards or downwards, reshaped, or resized in other aspects.

FIG. 5 is a cross-section of the pre-assembled coupling assembly 100 of FIG. 1 and the pipe 500 taken along line 5-5 shown in FIG. 3. The housing 171 can define a ridge 578a disposed at the first end 178a of the housing 171 and a ridge 578b disposed at the second end 178b of the housing 171. The ridges 578a,b can extend radially inward relative to the axis 101. The housing 171 can define a gasket groove 570 within the coupling bore 182 which can be disposed between the ridges 578a,b, and the gasket 140 can be seated within the gasket groove 570.

The gasket 140 can define a sealing ridge 548a disposed proximate to the first end 178a of the housing 171 and a sealing ridge 548b disposed proximate to the second end 178b of the housing 171. The sealing ridges 548a,b can extend radially inward from the gasket 140 relative to the axis 101. The gasket 140 can also define a center ridge 540 disposed between the sealing ridges 548a,b. The center ridge 540 can extend radially inward from the gasket 140, and the center ridge 540 can define a pair of ribs 550a,b at a radially innermost end of the center ridge 540. The gasket 140 can define a sealing channel 552a disposed between the sealing ridge 548a and the rib 550a and a sealing channel 552b disposed between the sealing ridge 548b and the rib 550b.

The pipe 500 can define an inner pipe surface 506 and an outer pipe surface 504 disposed opposite from the inner pipe surface 506. The inner pipe surface 506 can define a pipe bore 510 extending through the pipe 500, and the pipe bore 510 can carry pressurized fluids through the piping system. A circumferential groove 508 can be defined extending radially inward into the outer pipe surface 504 relative to the axis 101. The groove 508 can be disposed proximate to the end 502 of the pipe 500. The ridge 578b can be configured to engage the groove 508 when the end 502 of the pipe 500 is inserted into the coupling bore 182 and the coupling 170 is in the tensioned position. When engaged with the groove 508, the ridge 578b secures the coupling 170 to the pipe 500 and prevents axial movement of the pipe 500 relative to the coupling 170.

The cap 112 can define an outer end 516a disposed external to the coupling bore 182 and an inner end 516b disposed within the coupling bore 182. The cap 112 can define an outer lip 512 which can extend radially outward from the cap 112 proximate to the outer end 516a. In the present aspect, the outer lip 512 can radially overlap with the first ridge 578a of the housing 171 when the coupling 170 is in the relaxed position. The outer lip 512 can provide a physical stop which can thereby prevent the outer end 516a of the cap 112 from entering the coupling bore 182.

The cap 112 can define a raised lip 518 disposed at the inner end 516b, and the raised lip 518 can extend radially outward from the inner end 516b relative to the axis 101. In the present aspect, the raised lip 518 can be disposed radially inward from the outer lip 512, therefore allowing the inner end 516b and the raised lip 518 to be inserted into the coupling bore 182 with the coupling 170 in the relaxed position. In other aspects, the raised lip 518 can extend radially outwards beyond the first ridge 578a with the coupling 170 in the relaxed position, thereby preventing insertion and removal of the inner end 516b from the coupling bore 182. In such aspects, the first segment 172a and the second segment 172b of the housing 171 can be assembled around the inner end 516b of the cap 112 to capture the inner end 516b within the coupling bore 182. In such aspects, the inner end 516b of the cap 112 may not be removed from the coupling bore 182 without disassembling the housing 171.

The raised lip 518 can be sized to radially interfere with the sealing ridge 548a of the gasket 140 when the gasket 140 is in the relaxed and uncompressed state. For example, a radially outermost portion of the raised lip 518 can be disposed radially outward from a radially innermost portion of the sealing ridge 548a when the raised lip 518 is axially positioned between the sealing ridges 548a,b relative to the axis 101. The gasket 140 can comprise an elastic material, such as a rubber, a polymer, an elastomer, or any other suitable material, and the gasket 140 can be flexible and resilient.

Interference between the raised lip 518 and the sealing ridge 548a can prevent accidental removal of the inner end 516b of the cap 112 from the coupling bore 182 when the coupling 170 is in the relaxed position. The sealing ridge 548a can stretch over the raised lip 518 when the inner end 516b is inserted into or withdrawn from the coupling bore 182. In the present aspect, the sealing ridge 548a can be in a relaxed state when the coupling 170 is in the relaxed position, and the sealing ridge 548a is axially positioned between the raised lip 518 and the outer lip 512 of the cap 112 relative to the axis 101.

In the present aspect, the inner end 516b of the cap 112 can be withdrawn from the coupling bore 182 of the coupling 170 with a deliberate force when the coupling 170 is in the relaxed position. By exerting the deliberate force, the sealing ridge 548a can stretch over the raised lip 518 to allow the cap 112 to be removed from the coupling 170. The resistance provided by the sealing ridge 548a can be optimized to prevent accidental disassembly of the pre-assembled coupling assembly 100 while still allowing for deliberate disassembly of the pre-assembled coupling assembly 100 without undue difficulty. For example, with the coupling 170 in the relaxed position, the pre-assembled coupling assembly 100 can be disassembled with the fingers of a user possessing typical hand strength without the need for tools while also resisting separation of the coupling 170 from the cap 112 by the force of gravity and general handling of the pre-assembled coupling assembly 100. For example, the coupling 170 and the cap 112 can resist separation if a user carries the pre-assembled coupling assembly 100 without supporting both the coupling 170 and the cap 112.

In the present aspect, the cap 112 can define a groove 514 extending radially inward into the cap 112 between the outer lip 512 and the raised lip 518. The groove 514 can be configured to receive the first ridge 578a of the housing 171 when the coupling 170 is in the tensioned position. Engagement between the first ridge 578a and the groove 514 can secure the cap 112 to the coupling 170 and prevent the inner end 516b of the cap 112 from being withdrawn from the coupling bore 182 when the coupling 170 is in the tensioned position.

The groove 514, the outer lip 512, and the raised lip 518 can each be defined by an annular ring 532 of the cap 112. The annular ring 532 can extend circumferentially around radially outer portions of the cap 112. A web 530 can be defined within the annular ring 532, and the web 530 can enclose the annular ring 532. In the present aspect, the web 530 can be a dished web 531, which can define a convex shape when viewed from the outer end 516a and a concave shape when viewed from the inner end 516b.

The raised lip 518 can define at least one pressure relief channel 520 defined at the inner end 516b of the cap 112. The pressure relief channel 520 can extend through the raised lip 518 as shown and further described with respect to FIGS. 10 and 11 below.

FIG. 6A is a detailed cross-sectional view of the pipe 500, the cap 112, and the coupling 170 of FIG. 5 with the coupling 170 in the tensioned position and with the pre-assembled coupling assembly 100 in a pressurized condition in which fluid is allowed to flow into the pipe 500 to apply fluid pressure to the cap 112 and the gasket 140. In the tensioned position, the gasket 140 can be compressed radially inward to form seals with the pipe 500 and the cap 112. The sealing ridge 548a can form a seal with a sealing surface 612 defined by the cap 112. In the present aspect, the sealing surface 612 can be defined between the raised lip 518 and the groove 514, and the raised lip 518 can extend radially outward from the sealing surface 612. The sealing ridge 548b can form a seal with a sealing portion 604 of the outer pipe surface 504 of the pipe 500 defined between the groove 508 and the end 502 of the pipe 500. The raised lip 518 can also define a ramped surface 619. The ramped surface 619 can be angled, as shown in FIG. 6A, thereby taking the shape of a truncated cone, or can be curved in other aspects. The angle or curve of the ramped surface 619 can be configured to guide the sealing ridge 548a into position around the sealing surface 612 as the cap 112 is inserted into the coupling 170, and the gasket 140 can also be configured to prevent removal of the gasket 140 from over the raised lip 518 when the gasket 140 is in the relaxed position.

The outer lip 512 can also define a ramped surface 613 facing axially towards the pipe 500. The ramped surface 613 can also define a side of the groove 514 axially outward from the coupling 170. The ramped surface 613 can be angled, as shown in FIG. 6A, thereby taking the shape of a truncated cone, or can be curved in other aspects, and can extend to a bottom of the groove 514. The angle or curve of the ramped surface 613 can be configured to guide the first ridge 578a into position in the groove 514 when the coupling 170 is tightened into the tensioned position. The ramped surface 613 can thereby function as a locating feature to allow the user to ensure that the coupling 170 is properly positioned over the cap 112 and, when the pipe 500 is inserted into the coupling 170 to abut the cap 112, as shown in FIG. 6B, the coupling 170 is likewise properly positioned over the pipe 500 such that the ridge 578b is aligned over the groove 508. Thus, when the coupling 170 is tightened into the tensioned position, the ridge 578b can be properly guided into the groove 508. In various aspects, the groove 514 can be narrower in the axial direction than the groove 508 so that the ridge 578b can be spaced slightly in the axial direction from sides of the groove 508. This can ensure that the ridge 578b properly seats into the groove 508 without inadvertently contacting sides of the groove 508 when the coupling 170 is tightened.

Further, the grooves 508,514 of the pipe 500 and the cap 112, respectively, can each define side stop surfaces 609,615, respectively. The side stop surfaces 609,615 act as stops to prevent the pipe 500 and the cap 112, respectively, from being removed from the coupling 170 when the coupling 170 is in the tensioned position by engaging the ridges 578a,b when either or both of the pipe 500 and the cap 112 are pushed or pulled axially outward from the coupling 170, such as when the pre-assembled coupling assembly 100 is in the pressurized condition.

FIG. 6A also shows that portions of the first segment 172a and, similarly, the second segment 172b can contact outer surfaces of the pipe 500 and the cap 112 adjacent to the grooves 508,514, respectively, when the coupling 170 is in the tensioned condition. However, in other aspects, the segments 172a,b may contact only one or both of the grooves 508,514, or contact the groove 508 and the outer surface of the cap 112 adjacent to the groove 514, or contact the groove 514 and the outer surface of the pipe 500 adjacent to the groove 508.

In the tensioned position, the center ridge 540 can be compressed radially inward, and the rib 550a can contact the raised lip 518. In some aspects, the rib 550a can form a secondary seal with the raised lip 518. In the present aspect, the pressure relief channel 520 can maintain fluid communication between the sealing channel 552a and the pipe bore 510. By maintaining fluid communication between the sealing channel 552a and the pipe bore 510, pressurized fluids carried by the pipe 500 can exert pressure within the sealing channel 552a which can energize the seal formed between the sealing ridge 548a and the sealing surface 612 of the cap 112. The scaling channel 552a can define a U-shape of the sealing ridge 548a, and pressure exerted within the sealing channel 552a can press an axially inner end 648a of the sealing ridge 548a against the scaling surface 612. The sealing ridge 548b can function similarly, and pressurized fluids within the sealing channel 552b can press an axially inner end 648b of the sealing ridge 548b against the sealing portion 604 of the outer pipe surface 504 of the pipe 500 to energize the seal between the scaling ridge 548b and the pipe 500.

FIG. 6B is a detailed cross-sectional view of the pipe 500 and the coupling 170 of FIG. 5 and another aspect of the cap 112, with the coupling 170 in the relaxed position with the pipe 500 inserted into the coupling 170 and abutting the cap 112. The cross-section of FIG. 6B is taken from a sectional line extending through mid-sections of the first segment 172a and the second segment 172b (shown in FIG. 1). When the pipe 500 is inserted into pre-assembled coupling assembly 100 with the pipe fitting 110, the end 502 of the pipe 500 abuts the inner end 516b of the pipe fitting 110, which is a cap 112 in the current aspect. With the ramped surface 619 preventing withdrawal of the gasket 140 and thereby the coupling 170, and with the ramped surface 613 preventing further insertion of the cap 112 into the coupling 170, the pipe 500 can thereby be held in position to locate the ridge 578b over the groove 508. In the current aspect, the scaling ridge 548b can also be in contact with the scaling surface 612 when the coupling 170 is in the relaxed position, further holding the cap 112 in the coupling 170.

As shown in FIG. 6B, in some aspects, the bottom of the groove 514 can define a smaller diameter than a bottom of the groove 508. This can provide the benefit of the ridge 578b rigidly contacting the pipe 500 before the ridge 578a contacts the cap 112, ensuring that the coupling 170 is rigidly attached to the pipe 500. The sealing surface 612 of the cap 112 can also define a larger diameter than the sealing portion 604 of the pipe 500, which can better hold the gasket 140, and thereby the coupling 170, on the cap 112. The diameter of the sealing surface 612 can be sized such that the gasket 140 contacts the sealing surface 612 in the relaxed position, or can be sized such that the gasket 140 does not contact the sealing surface 612 in the relaxed position but is closer to the gasket 140 than the sealing portion 604.

FIG. 7 is a cross-sectional view of another aspect of the cap 112 in accordance with another aspect of the present disclosure. In the aspect shown, the web 530 of the cap 112 can be a planar web 730. FIG. 8 is a cross-sectional view of the cap 112 of the aspect of FIG. 5. FIG. 9 is an end view of the cap 112 of FIG. 5 facing the inner end 516b of the cap 112. As shown, the cap 112 can define a plurality of pressure relief channels 520 defined into the raised lip 518. In the present aspect, the cap 112 can define four pressure relief channels 520 which can be equally circumferentially spaced around the raised lip 518. In other aspects, the cap 112 can define greater or fewer than four pressure relief channels 520, and the pressure relief channels 520 can be distributed in any suitable configuration around the raised lip 518.

FIG. 10 is a detail cross-sectional view of a one of the pressure relief channels 520 of FIG. 9 taken along line C-C shown in FIG. 9. The pressure relief channel 520 can comprise an angled surface 1020 and an axial surface 1018. The angled surface 1020 can be angled relative to the inner end 516b of the cap 112 and relative to the sealing surface 612. In the present aspect, the angled surface 1020 can define a 30-degree angle with the inner end 516b of the cap 112; however, in other aspects, the angle can be larger or smaller than 30 degrees. The axial surface 1018 can be substantially parallel to the axis 101 (shown in FIG. 9) and the sealing surface 612. The axial surface 1018 can be defined radially outward from the scaling surface 612 of the cap 112 and radially inward from the raised lip 518.

The raised lip 518 can define a rounded transition surface 1016 defined at the inner end 516b of the cap 112. The raised lip 518 can define the ramped surface 619 extending to the sealing surface 612. In the present aspect, the ramped surface 619 can define a 45-degree angle with the sealing surface 612; however, in other aspects, the angle can be greater or smaller than 45 degrees.

FIG. 11 is a detail cross-sectional view of another aspect of the pressure relief channels 520 of FIG. 9 taken along line C-C shown in FIG. 9. Rather than defining the angled surface 1020 as shown in FIG. 10, the pressure relief channel 520 can define a radial surface 1120 which can be substantially perpendicular to the axis 101 (shown in FIG. 9) and the axial surface 1018. In the present aspect, the radial surface 1120 can be substantially parallel to the inner end 516b. In the present aspect, the radial surface 1120 can extend completely across the inner end 516b of the annular ring 532 of the cap 112.

FIGS. 12A-12H show multiple views of the cap 112 of FIG. 1 and the drain cap 212 of FIG. 2. Each of the cap 112 and the drain cap 212 can define either the dished web 531 or the planar web 730 or any other suitable shape.

FIGS. 13A-13E show another aspect of the pre-assembled coupling assembly 100 wherein the pipe fitting 110 is a domed cap 1312. The domed cap 1312 can define a domed portion 1310 disposed at the outer end 516a of the domed cap 1312 and a cylindrical portion 1314 disposed at the inner end 516b of the domed cap 1312. The domed cap 1312 can define a secondary key 1378 extending radially outward from cylindrical portion 1314. The secondary key 1378 can be disposed adjacent to the groove 514, and the groove 514 can be disposed between the secondary key 1378 and the inner end 516b.

The coupling 170 can comprise a grooved housing 1371 comprising another aspect of the first segment 172a and the second segment 172b. The grooved housing 1371 can define a secondary shoulder 1370 attached to the first ridge 578a. A secondary groove 1372 can be defined between the secondary shoulder 1370 and the first ridge 578a. The secondary key 1378 can be received within the secondary groove 1372 to retain the coupling 170 on the domed cap 1312.

During assembly, the coupling 170 in the relaxed position can be slipped over the end 502 of the pipe 500, and the end 502 can be positioned in facing engagement with the inner end 516b of the domed cap 1312. With the end 502 in facing engagement with the inner end 516b, the secondary key 1378 can be positioned adjacent to the first ridge 578a. Once the coupling 170 is in the tensioned position and the pipe 500 is pressurized, the domed cap 1312 can pull away from the end 502 of the pipe 500 due to end cap forces from pressurized fluids transmitted by the pipe 500. Contact between the secondary key 1378 and the secondary shoulder 1370 can limit axial movement of the domed cap 1312 relative to the coupling 170 and the pipe 500.

FIGS. 14A-14D show multiple views of another aspect of the pre-assembled coupling assembly 100. The pipe fitting 110 can be a recessed cap fitting 3012, which can define a recessed raised-lip end 3002 and an outer lip end 3004. The outer lip end 3004 can define the outer lip 512, and the outer lip end 3004 can be disposed axially outward from the coupling 170 with respect to the axis 101. The recessed cap fitting 3012 can define a shoulder 3060 disposed between the sealing surface 612 and the raised lip 518. The shoulder 3060 can extend radially inward from the sealing surface 612 with respect to the axis 101. The recessed cap fitting 3012 can further define a groove 3014 axially disposed between the raised lip 518 and the shoulder 3060 with respect to the axis 101. The groove 3014 can extend radially inward from the raised lip 518 with respect to the axis 101.

In the present aspect, the raised lip 518 can be a recessed raised lip 3018 disposed radially inward from the sealing surface 612 with respect to the axis 101. The pressure relief channels 520 can be recessed pressure relief channels 3020 which can radially extend through the recessed raised lip 3018 and can axially extend between the recessed raised-lip end 3002 and the shoulder 3060 with respect to the axis 101.

In the present aspect, the gasket 140 can be a rimmed gasket 3040. The rimmed gasket 3040 can define an inner rim 3050 which can extend radially inward from the center ridge 540 of the rimmed gasket 3040. The inner rim 3050 can define a radially inner end 3052. With the recessed raised-lip end 3002 disposed within the coupling bore 182, the inner rim 3050 can be positioned adjacent to the shoulder 3060. The radially inner end 3052 of the inner rim 3050 can be received within the groove 3014 of the recessed cap fitting 3012, and the recessed raised lip 3018 can radially overlap with the radially inner end 3052 of the inner rim 3050 with respect to the axis 101. Radial overlap of the recessed raised lip 3018 and the radially inner end 3052 can retain the coupling 170 on the recessed cap fitting 3012 when the coupling 170 is in the relaxed position.

The end 502 of the pipe 500 can also be inserted into the coupling bore 182 with the coupling 170 in the relaxed position. With the end 502 of the pipe 500 disposed within the coupling bore 182, the inner rim 3050 can extend axially inwards from the rimmed gasket 3040 between the end 502 of the pipe 500 and the shoulder 3060, thereby preventing contact between the end 502 of the pipe 500 and the shoulder 3060. The recessed raised-lip end 3002 can be inserted into the end 502 of the pipe 500. The recessed raised lip 3018 can define a tapered pipe alignment surface which can facilitate insertion of the recessed raised-lip end 3002 of the recessed cap fitting 3012 into the end 502 of the pipe 500.

FIGS. 15A-15D show multiple views of another aspect of the pre-assembled coupling assembly 100. The coupling 170 of the present aspect of the pre-assembled coupling assembly 100 can comprise a C-style gasket 3140 which may not define the center ridge 540 (shown in FIG. 5) of the gasket 140 (shown in FIG. 5). The C-style gasket 3140 can define a pair of sealing ridges 3148a,b. In the present aspect, the sealing ridges 3148a,b can extend axially and radially inward relative to the axis 101, as demonstrated by sealing ridge 3148b, when the C-style gasket 3140 is in a relaxed and uncompressed state. Once the end 502 of the pipe 500 is inserted into the coupling 170, the sealing ridge 3148b can stretch over the end 502 of the pipe 500 and rotate radially outward with respect to the axis 101.

FIGS. 16A-16C show multiple views of another aspect of the pre-assembled coupling assembly 100 wherein the pipe fitting 110 can be a grooved pipe cap 3212. The grooved pipe cap 3212 can define an inner end 3202 and an outer end 3204, and the inner end 3202 can be disposed opposite from the outer end 3204 on the grooved pipe cap 3212. A circumferential groove 3222 can be defined at the inner end 3202, and the circumferential groove 3222 can extend around a circumference of the grooved pipe cap 3212. The circumferential groove 3222 can be defined extending radially inward from the sealing surface 612. In the present aspect, the circumferential groove 3222 can define a triangular cross-sectional shape; however in other aspects, the circumferential groove 3222 can define a different cross-sectional shape, such as semi-circular, rectangular, or any other suitable shape. In the present aspect, the raised lip 518 can be a recessed raised lip 3218 disposed radially inward from the sealing surface 612 with respect to the axis 101. The inner end 3202 can also define pressure relief channels 3220 extending radially through the inner end 3202 and intersecting the circumferential groove 3222 with respect to the axis 101. With the end 502 of the pipe 500 inserted into the coupling 170, the end 502 of the pipe 500 can contact the inner end 3202 of the grooved pipe cap 3212.

The coupling 170 can comprise a modified rimmed gasket 3240, which can define an inner rim 3250 which can extend radially inward from the center ridge 540 with respect to the axis 101. A radially inner end 3252 of the inner rim 3250 can define a cross-sectional shape formed complimentary to the cross-sectional shape of the circumferential groove 3222. In the present aspect, the radially inner end 3252 can define the triangular cross-sectional shape for example and without limitation. The radially inner end 3252 of the inner rim 3250 can engage the circumferential groove 3222, and engagement between the radially inner end 3252 and the circumferential groove 3222 can retain the coupling 170 on the inner end 3202 of the grooved pipe cap 3212 when the coupling 170 is in the relaxed position.

FIG. 17A is a perspective view of another aspect of the cap wherein the cap is a stop lip cap 1712 in accordance with another aspect of the present disclosure. FIG. 17B is a side view of the stop lip cap 1712 of FIG. 17A. On the stop lip cap 1712, the raised lip 518 can be a stop lip 1718. The stop lip 1718 can be spaced axially inward towards the outer end 516a and away from the inner end 516b relative to the axis 101. The pressure relief channels 520 can also be defined by circumferential gaps 1720 in the stop lip 1718 in the present aspect.

FIG. 17C is a cross-sectional view of the stop lip cap 1712 taken along line 17C-17C shown in FIG. 17A. Unlike the raised lip 518 of the aspects of the cap 112 of FIGS. 1-12H, in this aspect, the raised lip 518, stop lip 1718, does not extend to the inner end 516b. Instead, a step surface 1716 can be defined between the stop lip 1817 and the inner end 516b. In the present aspect, the step surface 1716 can be a cylindrical surface. In the present aspect, the step surface 1716 can be radially aligned with the sealing surface 612; however in other aspects, the step surface 1716 can be defined radially inward or radially outward from the sealing surface 612. In the present aspect, the step surface 1716 can be defined radially outward from the groove 514 but radially inward from the stop lip 1718 and the outer lip 512. In the present aspect, the stop lip 1718 can extend radially outwards even with the outer lip 512; however in other aspects, the stop lip 1718 can extend radially outwards beyond the outer lip 512.

The stop lip 1718 can define an outer surface 1719a facing the outer end 516a of the stop lip cap 1712 and an inner surface 1719b facing the inner end 516b of the stop lip cap 1712. The outer surface 1719a can define an outer angle A₁relative to a radial direction of the axis 101, and the inner surface 1719b can define an inner angle A₂relative to the radial direction of the axis 101. In the present aspect, each of the angles A₁, A₂can be less than 45 degrees. In some aspects, the angles A₁, A₂can be 0 degrees, and the inner surface 1719a and the outer surface 1719b can be parallel to the radial direction of the axis 101.

FIG. 18A is an end view of an aspect of the pre-assembled coupling assembly 100 comprising the stop lip cap 1712 of FIGS. 17A-C. FIG. 18B is a cross-sectional side view of the pre-assembled coupling assembly 100 of FIG. 18A taken along line 18B-18B shown in FIG. 18A with the pipe 500 of FIG. 5. In the present aspect, the stop lip 1718 can be specifically shaped to prevent insertion and withdrawal of the inner end 516b of the stop lip cap 1712 into the coupling bore 182 when the coupling 170 is in the relaxed position. For example, the stop lip 1718 can extend radially outward far enough to radially overlap with the ridge 578a. Consequently, if a user attempts to insert the inner end 516b into the coupling bore 182 in the relaxed state or remove the inner end 516b from the coupling bore 182 in the relaxed state, interference between the stop lip 1718 and the ridge 578a will prevent the user from succeeding. Instead, the user must disassemble the coupling 170 by separating the first segment 172a from the second segment 172b of the housing 171 to insert or remove the inner end