Inner seal and support rod assembly for high pressure blowout preventers

A new and improved inner seal and support rod assembly for a blowout preventer including an inner seal assembly for improved sealing and configured to promote ease of maintenance and removal thereof in cooperation with substantially horizontally disposed, vertically aligned support rods of the blowout preventer.

TECHNICAL FIELD OF THE INVENTION 
The field of this invention relates to blowout preventers, and more 
particularly to inner seal and support rod assemblies thereof. 
PRIOR ART 
Blowout preventers of many types and configurations are well known in the 
art. In the prior art, it is not unusual that an inner seal be mounted 
with a ram body used to close the annulus within the blowout preventer 
during typical operations thereof. So far as known, prior art inner seal 
arrangements have included many types of sealing materials. Most notably, 
such seals have been a combination of sandwiched materials with a metal 
upper and lower member being secured with a resilient sealing material and 
typically of a substantially rectangular cross-sectional configuration. 
The upper and lower metal members are conventionally bonded with the 
resilient sealing material. Furthermore, it is known that the resilient 
material preferably be in full face engagement with the ram body to 
enhance a sealing relationship between the inner seal/ram body and tubular 
member to be sealed off upon actuation of the blowout preventer. 
The prior art also teaches the use of pins or fasteners extending through 
the ram body into the inner seal for locating the inner seal with the ram 
body. Examples of such an arrangement are shown in the December 1981 
instruction manual No. 5/8523 of Bowen Tools, Inc., entitled "Bowen 
Snubbing Blowout Preventers". Typically, a substantially rectangular 
opening is formed in the ram body to receive the inner seal assembly and 
the inner seal is typically appropriately positioned and secured with the 
ram body by means of retainer screws, pins and the like to ensure proper 
location and orientation of the inner seal with respect to the ram body. 
Furthermore, as is known, the ram body is mountable within a suitable 
preventer housing, with a pressure plate assembly with the preventer 
housing enclosing and permitting actuation of the ram of the blowout 
preventer. Removal of the pressure plate permits access to the ram body 
for maintenance of the ram body and its attendant seals. It is also shown 
in the aforementioned Bowen manual, that typically suitable support rods 
are mounted with the preventer housing and pressure plate to permit 
retraction of the pressure plate to expose the ram body for seal 
replacement. In the prior art it is known that such support rods, so far 
as known, have been mounted with the preventer body in the same horizontal 
plane as that of the ram body. As such, upon retraction of the pressure 
plate, the removal of the inner seal for replacement becomes a difficult 
maintenance item particularly in view of typical stack arrangements of 
blowout preventers, as shown schematically on page 13 of the Bowen manual. 
As such, access to the ram body is restrained and removal of the inner 
seal assembly is sometimes difficult if not impossible without requiring 
significant effort in order to effectuate seal maintenance and removal. 
SUMMARY OF THE INVENTION 
The present invention relates to an new and improved inner seal and rod 
assembly for a blowout preventer that enhances inner seal effectiveness 
while providing a seal that is easily removed from the ram body for 
maintenance. A feature of the present invention includes vertically 
oriented support rods that permit the lateral extraction of the inner seal 
assembly from the ram body to enhance seal removal operations.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, the letter A designates generally the inner seal 
assembly and the letter R refers generally to the support rod assembly of 
the present invention as adapted to be used in conjunction with a blowout 
preventer B. The blowout preventer B generally includes a preventer body P 
that is adapted to receive a ram body D having the inner seal assembly A 
therewith. A pressure plate C secures the ram body D with the preventer 
body P. The ram body D is adapted to be supportably mounted by the 
pressure plate C upon disassembly thereof. Unless otherwise noted, the 
components of the blowout preventer B are preferably made of suitable high 
strength materials capable of withstanding the typically high stresses and 
strains encountered in normal blowout preventer operations. 
The inner seal assembly A and support rod assembly R of the present 
invention are adapted to be used with the blowout preventer B. The blowout 
preventer B includes a preventer body P which includes body 10. The body 
10 (FIGS. 1, 2) includes an upper flange 10a and lower flange 10b for 
mounting the preventer body P with other blowout preventers or flanged 
tubular members as is necessary. The body 10 is formed having a 
substantially vertical central bore 10c which is adapted to receive a 
tubular member (not shown) therein. The upper and lower flanges 10a, 10b 
are joined with the central body member 10d by body extensions 10e, 10f, 
respectively. The central body member 10d is formed having body sides 10g, 
10h, 10i, 10j. Preferably an opening 10k is formed with side 10g and 
communicates therefrom to a central bore 10c, much as opening 10l 
communicates from side 10i to central bore 10c. Suitable capping flanges 
(not shown) are adapted to be secured with sides 10g, 10i adjacent to 
openings 10k, 10l, respectively by means of threaded bolts (not shown) 
being receivably mounted in threaded openings 10m, 10n, respectively for 
appropriately covering the openings 10k, 10l during blowout preventer 
operations. The sides 10h, 10j of the body 10 of the preventer body P 
communicate by means of a substantially horizontal ram bore 10o which 
extends between such sides 10h, 10j and intersects the central bore 10c of 
the body 10, as best seen in FIG. 5. A plurality of threaded openings 10p 
are disposed about the ram bore 10o and for receiving pressure plate bolts 
12, as discussed more fully hereinbelow. It is preferred that the threaded 
openings 10p be in an axially parallel orientation with respect to the ram 
bore 10o and disposed in a substantially square pattern about the ram bore 
10o. As discussed more fully hereinbelow, the ram body D is adapted to be 
mounted within the ram bore 10o of the body 10. The body 10 is further 
formed having threaded openings 10q (FIG. 5) for receiving piston rod 14. 
Preferably, the piston rod 14 has a threaded end 14a for being received in 
threaded opening 10q of the preventer body P. The piston rod 14 has a 
piston end 14b with a central bore 14c extending between the threaded end 
14a and piston end 14b. As will be discussed more fully hereinbelow, 
preferably there are two piston rods 14 such as rods 14r, 14s on side 10h 
and two piston rods 14 such as rods 14t, 14u on side 10j of the body 10 of 
the preventer body P with the rods 14r, 14s being horizontally opposed and 
in axial alignment with rods 14t, 14u, respectively. Preferably the piston 
rods 14 have the longitudinal axis thereof parallel with that of the ram 
bore 10o, however, are situated in a vertical plane with respect to one 
another on each side as will be discussed more fully hereinbelow. 
The blowout preventer B further includes a pressure plate C including plate 
16 and rear body 18. The plate 16 and rear body 18 are adapted to be 
joined together and receive a suitable piston sleeve 20 therein for 
receiving piston rod 14 therein. Compatibly formed openings (not numbered) 
within the plate 16 and 18 permit proper location of the piston sleeve 20 
to ensure a fluid tight relation between the piston end 14b of the piston 
rod 14 and the bore 20a of the piston sleeve 20. A piston housing 22 is 
mounted with the rear body 18 to fully enclose the piston sleeve 20 and to 
provide appropriate fluid communication between the piston sleeve 20, rear 
body 18 and plate 16. The rear body 18 is formed having a piston sleeve 
chamber 18a therein adjacent to stem lock opening 18b. A compatibly formed 
piston sleeve chamber 16a is formed in plate 16 of the pressure plate C 
having a rod opening 16b formed adjacent thereto. A piston sleeve 24 is 
adapted to be sealably disposed within the piston sleeve chamber 16a, 18a 
of the plate 16 and rear body 18, respectively. A pair of horizontally 
opposed, axially aligned actuating rods 26 are used with the blowout 
preventer B. Each actuating rod 26 has a stem 26a, piston surfaces 26b, 
26c, rod 26d and ram body head 26e is mounted with the rear body 18 and 
plate 16 such that the stem 26a is mountable within stem lock opening 18b. 
Piston surfaces 26b, 26c having annular piston surface 26f therebetween, 
are disposed within the bore 24a of the piston sleeve 24, with rod 26d 
disposed within rod opening 16b and extending from rod opening 16b into 
the body 10, with the ram body head 26e adapted to engage the ram body D. 
A suitable stem cap 28 is secured with the rear body 18 by stem cap 
fasteners 28a. The stem cap 28 is preferably formed having a chamber 28b 
therein and adapted to receive the stem 26a of the actuating rod 26. The 
step cap 28 is further formed having a threaded opening 28c adjacent the 
chamber 28b for receiving stem lock 30. The stem lock 30 is preferably 
formed having threads 30a on the exterior thereof and adapted to be 
compatibly received within threaded opening 28c of stem cap 28. A tool 
engaging surface 30b is formed adjacent one end thereof while a stem 
receiver 30c is formed adjacent the opposite end thereof. The stem 
receiver 30c of the stem lock 30 is adapted to engage the stem end 26g of 
the stem 26a under conditions described more fully hereinbelow. Suitable 
seal means 32 and packing means 34 insure proper sealable action between 
the actuating rod 26 and the rear body 18 and plate 16. 
The actuating rod 26 is movable between an actuated position (as shown in 
FIG. 5A) and a retracted (as shown in FIG. 5B). When the actuating rod 26 
is in the actuated position of FIG. 5A, piston surface 26c is adjacent to 
the end surface 16c of piston sleeve chamber 16a of plate 16, with the 
stem end 26g of the actuating rod 26 near opening 18b of the rear body 18, 
while ram body head 26e of the actuating rod 26 is adapted to extend into 
the preventer body P with the ram body B. On the other hand, when the 
actuating rod is in a retracted position as shown in FIG. 5B, piston 
surface 26b is adapted to be adjacent to end surface 18c of piston sleeve 
chamber 18a of the rear body 18, with the stem 26a extending well into the 
chamber 28b of the stem cap 28 and with the ram body head 26e being in 
close proximity to the plate 16 of the pressure plate C. Furthermore, a 
fluid passageway 16d is formed in the plate 16 to permit fluid 
communication between end surface 16c and first end 20b of the piston 
sleeve 20 while fluid passageway 18d is formed in the rear body 18 to 
permit fluid communication between the piston sleeve chamber 18a of the 
rear body 18 and the piston sleeve chamber 18e formed in rear body 18 and 
piston sleeve chamber 22a formed in piston housing 22. While for the 
purposes of explanation, the actuated and retracted positions are shown in 
FIGS. 5A, 5B, respectively, it should be understood that action of the 
blowout preventer B results in both actuating rods 26 simultaneously being 
either actuated or simultaneously being retracted in response to fluid 
pressure, as will be discussed more fully hereinbelow. 
The ram body D includes ram 36 formed having body head receptacle 36a (FIG. 
4) for receiving the ram body head 26e of the actuating rod 26 therein 
with a portion 26h of the rod 26d being received in rod receptacle 36b of 
the ram 36. Preferably, the ram body D is of a generally cylindrical 
configuration and is formed having an outer seal groove for receiving 
outer seal 38 therein for suitable sealing action between the ram 36 and 
ram bore 10o of the body 10, the ram 36 adapted to be disposed within the 
preventer body P. A suitable guide opening 36d is preferably formed with 
the lower end of the ram 36 and is adapted to receive a suitable key or 
the like (not shown) within the ram bore 10o for insuring proper 
orientation of the ram 36 with respect to the body 10 when fully assembled 
and during movement of the ram 36 between the actuated and retracted 
positions. The ram 36 is further formed having a front surface 36e, a rear 
surface 36f, and an outer annular surface 36g. Preferably the front 
surface 36e is formed having semicircular detent 36h that is of such a 
diameter that is slightly larger than the tubular members (not shown) that 
are to be sealed against upon actuation of the blowout preventer B. The 
inner seal assembly A of the present invention is adapted to be mounted 
with the ram body D by mounting such in the inner seal opening 36i formed 
in the ram 36. The inner seal opening 36i includes a rear surface 36j, an 
upper surface 36k, a lower surface 36l, an upper stepped surface 36n and 
a lower stepped surface 36n. As such, the inner seal opening 36i, as 
viewed in FIGS. 4, 7B is somewhat of a generally "T-shaped" configuration 
for receiving the inner seal assembly A of the present invention as 
discussed more fully hereinbelow. 
The inner seal assembly A of the present invention includes resilient 
sealing material S and mounting plates M as best seen in FIG. 6. It is 
preferred that the inner seal assembly A be symmetrically formed about the 
horizontal plane such that in a side elevational view as shown in FIG. 4, 
the upper half of the inner seal assembly A is identical with the lower 
half thereof except they are merely mirror images. As shown in FIG. 6, the 
inner seal assembly A is formed of a resilient sealing material S which 
includes sealing material 40, which may include rubber, or multiple 
composites thereof or any other suitable resilient material. Preferably 
the sealing material 40 is formed having a ram body engaging surface 40a, 
an upper ram seal bore engaging surface 40b, a lower ram seal bore 
engaging surface 40c, an upper mounting plate foot engaging surface 40d, a 
lower mounting plate foot engaging surface 40e, an upper mounting plate 
engaging surface 40f, lower mounting plate engaging surface 40g, inner 
bore surface 40i and inner seal surface 40j. As such, the ram body 
engaging surface 40a is adapted to abut the rear surface 36j of the inner 
seal opening 36i in ram 36. Preferably, the upper and lower ram seal bore 
engaging surfaces 40b, 40c are substantially perpendicular to the ram body 
engaging surface 40a. Preferably, the upper and lower mounting plate foot 
engaging surfaces 40d, 40e are substantially perpendicular to the upper 
and lower ram seal bore engaging surfaces 40b, 40c, respectively. 
Furthermore, preferably upper and lower mounting plate engaging surfaces 
40f, 40g are substantially perpendicular to the upper and lower mount 
plate foot engaging surfaces 40d, 40e, respectively. Inner bore surfaces 
40i and inner seal surfaces 40j are substantially perpendicular to and 
join the upper and lower mounting plate engaging surfaces 40f, 40g. As 
such, though somewhat out of scale as shown in FIG. 6, the sealing 
material 40 of the resilient sealing material S of the inner seal assembly 
A is somewhat of a "T-shaped" configuration as viewed in side elevational 
cross-section. 
Mounting plates M are adapted to be secured with the resilient sealing 
material S preferably by molding theretogether or any other suitable 
joining process. Preferably the mounting plates M include an upper 
mounting plate 42 and a lower mounting plate 44. The upper and lower 
mounting plates 42, 44 include inner foot surfaces 42a, 44a, inner seal 
engaging surfaces 42b, 44b, inner bore surfaces, 42c, 44c, outer ram 
engaging surfaces 42d, 44d, outer foot surfaces 42e, 44e, and, ram body 
foot surfaces 42f, 44f, respectively. As such, the inner foot surfaces 
42a, 44a of the upper and lower mounting plates 42, 44, respectively are 
adapted to engage upper and lower mounting plate foot engaging surfaces 
40d, 40e, respectively. Inner seal engaging surfaces 42b, 44b engage upper 
and lower mounting plate engaging surfaces 40f, 40g, with inner bore 
surfaces 42c, 44c in substantial vertical alignment with inner bore 
surface 40i. Thus, the inner foot surfaces 42a, 44a are substantially 
perpendicular with the inner seal engaging surfaces 42b, 44b, 
respectively, while the outer ram engaging surfaces 42d, 44d substantially 
parallel the inner seal engaging surfaces 42b, 44b, and the outer foot 
surfaces 42e, 44e substantially parallel the inner foot surfaces 42a, 44a. 
Ram body foot surfaces 42f, 44f are in substantial horizontal alignment 
with the upper and lower ram seal bore engaging surfaces 40b, 40c. Inner 
seal surfaces 42g, 44g are in substantial alignment with inner seal 
surface 40j of the sealing materials, which conforms substantially to that 
of the outer annular surface of the tubular member (not shown) adapted to 
be disposed in the central bore 10c. Thus, in side elevational 
cross-section, the upper mounting plate and lower mounting plate 44 are 
substantially of an "L-shaped" configuration. As such, the overall 
"T-shaped" inner seal assembly A is adapted to be mounted within the 
"T-shaped" inner seal opening 36i of the ram 36 of the ram body D. 
The support rod assembly R of the present invention includes the piston 
rods 14, the piston sleeves 20 and their respective piston housings 22. 
The piston housings 22 include housings 22b, 22c on side 10h and housing 
22d, 22e on side 10j. Housings 22b, 22d and 22c, 22e are adapted to be in 
substantially a horizontally opposed, axially aligned relationship with 
the blowout preventer B. As best illustrated in FIGS. 1 and 2, each of the 
two plate 16-rear body 18 assemblies as affixed to sides 10h, 10j of the 
body 10 of the preventer body P have a pair of support rod assemblies R 
mounted to one side of the actuating rod 26-ram body D assemblies. 
Preferably the support rod assemblies R of each side 10h, 10j are in 
substantially aligned axial relationships with its opposing member, 
however with the longitudinal axis of each of the rod assemblies R of one 
side of the blowout preventer B being situated in a substantially vertical 
plane. Thus the longitudinal axis of housings 22b and 22c of the rod 
assemblies R are substantially parallel and lie in a substantially 
vertical plane 45 (FIG. 2) as do housings 22d, 22e of side 10j of the body 
10. 
In the use or operation of the blowout preventer B, it is typical that such 
a blowout preventer B be used in combination with multiple blowout 
preventers B to form a stack of blowout preventers. As such the multiple 
blowout preventers are affixed with one another by means of upper and 
lower flanges 10a, 10b of the body 10 such that all central bores 10c of 
the blowout preventers B are in axial alignment with one another so that 
suitable tubular member (not shown) may be disposed within the central 
bore 10c of the blowout preventer B. As best seen in FIG. 5B, the blowout 
preventer B is initially positioned with the actuating rod 26 and ram 36 
in a retracted position. In this retracted position, the piston surface 
26b of the actuating rod 26 engages end surface 18c of rear body 18 and 
the rear surface 36f of the ram 36 is adapted to engage the pressure plate 
16 as the ram 36 is disposed within the ram bore 10o, yet leaving the 
central bore 10c unrestricted to permit the disposition of tubular members 
(not shown) therein. Fluid pressure in passageway 16d ensures this 
retracted positioning of the ram body D and actuating rod 26. When it is 
desired to actuate the blowout preventer B for sealing with the tubular 
member within the central bore 10c, fluid pressure flows through 
passageway 10r formed within the preventer body P, thereinto the central 
bore 14c of the piston rod 14 thereinto chamber 46 formed between piston 
sleeve chamber 22a of piston housing 22 and the piston sleeve 20, 
thereinto passageway 18d into chamber 48 formed between the piston sleeve 
24 and piston sleeve chamber 18a of the rear body 18 for reacting 
thereafter upon piston surface 26b of the actuating rod 26. Fluid pressure 
upon the piston surface 26b results in the actuating rod 26 moving 
upwardly as viewed in FIG. 5B to force the ram body D towards the central 
bore 10c of the body 10. Simultaneously, the opposing ram body D 
accomplishes the same result such that both ram bodies D close in response 
to the same fluid pressure during their respective engagement with the 
tubular member within the central bore 10c of the body 10. Because of 
commonality of passageways 10r, 14c, chambers 46, passageway 18d and the 
like, fluid pressure is balanced such that both opposing ram bodies D 
engage the tubular member substantially at the same time to in effect seal 
the annulus between the tubular member and the central bore 10c of the 
body by sealable engagement of the inner seal assembly A with the opposing 
inner seal assembly A and engagement with the tubular member. 
It should be appreciated that by the appropriate engagement of the tool 
engaging surface 30b of the stem lock 30 and the attendant rotation 
thereof, results in the stem receiver 30c engaging the stem end 26g to 
effectuate a mechanical closure of the ram body D by forcing such into the 
central bore 10c for appropriate sealing operations. This procedure may 
also be accomplished after the blowout preventer B has been hydraulically 
actuated and the ram body D is already actuated, yet the stem lock 30 will 
provide a mechanical assurance that the ram bodies D will remain closed. 
When it is desired to release the sealing pressure acting upon the ram 
body B, the stem lock 30 may merely be unthreaded and the fluid pressure 
introduced into fluid passageway 16d to permit retraction of the ram body 
D and actuating rod 26 from the central bore 10c of the preventer body P, 
as desired. 
As best depicted in FIG. 7B, upon the ram bodies B closing, the inner bore 
surfaces 42c, 44c as well as inner bore surface 40i engage one another in 
full face contact between the opposing inner seal assemblies A. As 
pressure is increased upon the ram body D, the inner seal assembly A 
experiences such pressure as being exerted through the rear surface 36j of 
the inner seal opening 36i in the ram 36. An increase in the closing force 
acting in the direction of arrows 50 in FIG. 7B results in a relative 
movement of the inner seal assembly A with respect to that of ram body D 
in the direction of arrows 52. This results not only from the closing 
force in the direction of arrows 50 but the resultant reactive force of 
the opposing inner seal assemblies A having full face contact along inner 
bore surfaces 42c, 44c, 40i and 42g, 44g, 40j. As the inner seal 
assemblies A react in the direction of arrows 52, the resilient sealing 
material S tends to flow in the direction of arrows 54, from that portion 
of the "L-shaped" mounting plates M towards the central bore 10c for 
enhanced sealing action in the same direction 50 of the closing force. 
Prior art seals, such as that shown in FIG. 7A have historically had a 
generally rectangular cross-sectional, side elevational configuration, 
such that in response to a closing force 50 acting upon a ram body, the 
prior art inner seal assemblies 72 would engage one another upon a 
substantially full face surface contact as on surface 56. This surface 56 
contact would result in a reactive force acting in the direction of arrows 
58 which would tend to flow the resilient sealing material 60 of the seal 
assembly 72 in the direction of arrows 62 in response to the mounting 
plates 64, 66 of the prior art seal assembly 72 moving in the direction of 
arrows 58. However, the prior art seal assemblies 72 were responsive to 
flow of resilient sealing material 60 due only to the limited surface area 
contact depicted by the dimensional arrow 68 between the mounting plates 
such as 64 and the resilient material 60. By utilization of the inner seal 
assembly A of the present invention, the area of contact as demonstrated 
by dimensional thickness 70 due to the "T-shaped" configuration of the 
overall inner seal assembly A, including not only the " T-shaped" 
resilient sealing material S but also the "L-shaped" mounting plates M, 
results in an increased area of contact pressure thus resulting a greater 
amount of "flow" of the resilient sealing material S upon closure of the 
ram body D for enhancing high pressure sealing. This area of contact 
pressure is defined by the height 70 multiplied by the overall width of 
the inner seal assembly A. Thus the ratio of the areas of the prior art 
seal 72 to the seal assembly A of the present invention is defined by a 
comparison of the thickness 68 to that of height 70, with that of 70 
defining a significantly greater amount to enhance sealing action. Seals 
such as this must be capable of operation under pressures up to twenty 
thousand pounds per square inch without failure in order to function as 
intended. Thus, by using the inner seal assembly A of the present 
invention, an improved high pressure sealing is effectuated upon closure 
of the ram body D upon actuation of the blowout preventer B. 
However, due to the high pressures typically encountered in such a blowout 
preventer B, it is necessary that the inner seal assembly A be positioned 
for ease of replacement and maintenance. Heretofore, as shown in FIG. 7A, 
typically a prior art seal assembly 72 is secured with the ram body by 
means of a suitable fastener 74 which extends through the ram body, into 
slot 66a formed in the mounting plate 66. Thus, in order to remove such a 
prior art seal assembly 72, the blowout preventer B must be partially 
disassembled in such a fashion that not only access may be easily had to 
the seal assembly 72 but also to the fastener 74 to result in maintenance 
and/or removal of the seal assembly 72. 
Prior art rod assemblies are typically positioned in the same horizontal 
plane as that of the ram body-actuating rod assembly and on both sides of 
this ram body-actuating rod assembly. As such, inner seal removal had to 
be accomplished by removal thereof along the longitudinal axis of the 
actuating rod (if the ram body was not removed) or removal of the ram body 
entirely from the blowout preventer was necessary prior to seal 
replacement. 
By utilizing the support rod assembly R with the blowout preventer B of the 
present invention, seal maintenance and removal operation is significantly 
improved, particularly in the instance where multiple, stacked blowout 
preventers B are utilized. As best seen in FIG. 5A when it is determined 
that there is a need to replace the inner seal assembly A of the present 
invention, the pressure plate blots 12 are removed from the threaded 
openings 10p, plate 16 and rear body 18. Thereafter, fluid pressure is 
introduced into passageway 10r and flows through central bore 14c of the 
piston rod 14. However, inasmuch as there are no pressure plate bolts 12 
to restrain movement of the plate 16 and rear body 18 with respect to body 
10, the pressure acting in chamber 46, passageway 18d and down to piston 
surface 26c is allowed to build, then backs up to react upon piston end 
14b of the piston rod 14 to apply a fluid pressure buildup within the 
chamber 46. As a result, the plate 16 and rear body 18 move outwardly with 
respect to the body 10 to result in an extraction of the ram body D from 
the preventer body P, with the support rod assembly R supporting the 
entire pressure plate C, rear body 18, actuating rod 26, ram body D 
assembly as shown expanded in FIG. 5A and FIG. 1. In this fully expanded 
position, the inner seal assembly A of the present invention may be 
removed by merely tapping the inner seal assembly A laterally such that 
the seal slides laterally within the inner seal opening 36i formed in the 
ram 36 of the ram body D. As such, the seal may be slid laterally between 
the piston rods 14r, 14s as shown in FIG. 1 or may alternatively by 
appropriate placement of a tool (not shown) between the vertically spaced 
piston rods 14, permit removal of the inner seal assembly A in the 
opposite lateral direction. Due to the "T-shaped" configuration of the 
inner seal assembly A of the present invention and the compatible opening 
36i in ram 36, no external fasteners such as fasteners 74 (FIG. 7A) are 
required to be removed, which typically pose extreme difficulties for 
removal when multiple blowout preventers B are stacked upon one another. 
Furthermore, the ram body D need not be removed from the actuating rod 26 
in order to accomplish the seal removal and replacement operation. Thus, 
the "T-shaped" inner seal opening 36i and "T-shaped" inner seal assembly A 
requires no additional fasteners to secure and properly position the inner 
seal assembly A with the ram body D. By using the inner seal assembly A of 
the present invention, the pressure plate bolts 12 need merely be removed 
and appropriate pressure applied to extract the ram body D from the 
preventer body P whereinafter the fully exposed ram body D may have the 
inner seal assembly A easily removed and extracted therefrom and be 
replaced with a new inner seal assembly A merely by forcing the seal 
laterally to and from the ram body D. The orientation of the support rod 
assembly R in the substantially vertical plane 45 (FIG. 2) with the 
actuation thereof paralleling the axis of the actuating rod 26 and ram 
body D, permits the ease of laterally replacing and maintencing the inner 
seal assembly A. 
Thus, the inner seal assembly A and support rod assembly R as used with a 
high pressure blowout preventer B provides for enhanced sealing action 
upon actuation of the blowout preventer B yet providing an inner seal 
assembly A capable of being easiliy maintained and replaced by field 
service personnel. 
The foregoing disclosure and description of the invention are illustrative 
and explanatory thereof, and various changes in the size, shape and 
materials, as well as in the details of the illustrated construction may 
be made without departing from the spirit of the invention.