WO2006033814A2

WO2006033814A2 - Adapter manifold with multi-valve block

Info

Publication number: WO2006033814A2
Application number: PCT/US2005/031448
Authority: WO
Inventors: David James Silva
Original assignee: David James Silva
Priority date: 2004-09-18
Filing date: 2005-09-02
Publication date: 2006-03-30
Also published as: WO2006033814A3

Abstract

An adapter manifold is provided comprising a dual valve block having a first and a second diaphragm valves, each of the diaphragm valves having a seat side and a diaphragm side, a first conduit connecting the first diaphragm side and the second seat side with the a first external source, a second conduit connecting the first seat side with a second external source, and a third conduit connecting the second diaphragm side with a third external source. An adapter manifold is further provided comprising a three valve block having three diaphragm valves, each of the diaphragm valves having a seat side and a diaphragm side, the first diaphragm side being juxtaposed to, and having flow communication with, the second diaphragm side and the third seat side, the first and second seat sides and the third diaphragm side being each connected to external sources by means of individual conduits.

Description

ADAPTER MANIFOLD WITH MULTI-VALVE BLOCK

Technical Field

The present invention concerns an adapter manifold with multi-valve block, and, more particularly, an adapter manifold for the delivery of a high purity chemical that has a multi-valve block, within which dead pockets exposed to the external environment are substantially eliminated.

Background Art Systems for the delivery of a high purity chemical typically employ a network of manifolds that comprise a plurality of valves and conduits. For example, in a semiconductor manufacturing process, a low vapor pressure, high purity chemical such as tetrakis(dymethilamino) titanium (TDMAT), tetrakis(diethylamino) titanium (TDEAT), tantalum pentaethoxide (TAETO), copper hexafluoroacetylacetonate-trimethylvinylsilane (Cu(hfac)TMVS), tetramethyltetracyclosiloxane (TMCTS), tetraethyl ortosilicate (TEOS), and trimethylphosphate (TMP) is delivered in liquid or vapor form from a primary storage container to a secondary storage container or to a process tool by means of manifolds, which comprise diaphragm valves regulating the flow of the chemical during ordinary process conditions, and the flow of purge gases and of vacuum during purge cycles. More particularly, in a semiconductor manufacturing process, a chemical having a

99.99+% purity level is stored in a primary container that has a capacity varying from 100 milliliters to 200 liters and that is known in the art by a variety of common and trade names, such as "canister," "ampoule," or "host." From the primary container, the chemical is distributed to a secondary container or to a process tool by means of a plurality of manifolds that also operate under high purity conditions.

From time to time, it is necessary to replace and clean the primary and/or secondary containers, for instance, for maintenance purposes, or because of the decomposition of the chemical stored in one of the containers, or for other reasons. Before detaching the container from the manifolds, any remaining chemical must be purged out of the manifolds connected to the container. Typically, a purge cycle is performed that comprises a sequence of blow and vacuum cycles. Due to the high level of decontamination required, and to prevent any residual chemical from remaining trapped within any dead spaces in the manifolds, the purge cyde is extremely time consuming, with a consequent negative effect on process yields.

It is therefore desirable to minimize the lengths of the connecting conduits within the manifolds, thereby reducing the areas of potential entrapment and/or adhesion of the chemical in the manifolds by consolidating two or more valves into a single valve block. It is also desirable to provide for more compact manifolds, in order to reduce the space requirements for the cabinets within which such manifolds and containers are generally located.

U.S. Patent No. 6,431 ,229 B 1 to Birtcher et al. discloses a purgeable adapter manifold for low vapor pressure chemicals that includes a dual valve block. As shown in Fig. 1, the dual valve block 10 according to Birtcher comprises a first diaphragm valve 12 and a second diaphragm valve 14 that each have orifices in the seats of the two diaphragm valves, such orifices being juxtaposed and connected by a first conduit 16.

A second conduit 18 connects the diaphragm side of second diaphragm valve 14 to a primary container, while a third conduit 20 connects first conduit 16 to a process tool or to a secondary container. During ordinary process conditions, both diaphragm valves 12 and 14 are in an open condition, enabling the low vapor pressure chemical to flow from second conduit 18 into first conduit 16 and into third conduit 20 and to be eventually delivered to a process tool or to the secondary container.

During the purge cycle, as a first step, purge gas is blown in a direction opposite to the flow during ordinary process conditions and travels from third conduit 20 into second conduit 18. As a second step, second diaphragm valve 14 is closed, and the purge gas flows from third conduit 20 into a fourth conduit 24 and then to a source of vent. As a third step, first diaphragm valve 12 and second diaphragm valve 14 are in set a closed condition, and a vacuum purge is performed by applying vacuum at third conduit 20, in order to remove any remaining traces of the low vapor pressure chemical.

It will be appreciated that, during the second step of the purge cycle, there is no gas flow through a portion of first conduit 16, more specifically, the portion delimited by third conduit 20 at one end and by orifice 26 in the seat of second diaphragm valve 14 at the other end. Therefore, that portion of first conduit 16 constitutes a dead pocket, from which any chemical remaining after the second step of the purge cycle can be removed only by means of a Venturi effect, whereby a pressure differential causes the residual chemical to be drawn from the dead pocket into the stream of the purge gas. In order to accomplish chemical removal through such Venturi effect, however, sufficient time must be allowed for the residual chemical to be drawn out of the dead pocket, causing the purge cycle to be extended. Further, the vacuum purge in the third step must always be performed, to insure that any residual chemical in the dead pocket, not displaced by the Venturi effect, is removed. The length of the vacuum purge depends on the amount of remaining chemical and on the desired cleanliness level, and requires pumps of adequate capacity with stainless steel components, due to the corrosive properties of the chemical.

Further, the Birtcher patent does not teach a three valve block system.

Disclosure of Invention

The present invention teaches an adapter manifold for the delivery of a high purity chemical that comprises a multi-valve block, within which dead pockets exposed to the external environment are substantially eliminated. In a first embodiment of the invention, an adapter manifold is provided that comprises a first dual valve block having a first and a second diaphragm valves, and further having a first conduit for connecting the diaphragm side of the first diaphragm valve as well as the seat side of the second diaphragm valve with the a first low dead space connector. A second conduit is also provided that connects the seat side of the first diaphragm valve with a second low dead space connector, and a third conduit is further provided that connects the diaphragm side of the second diaphragm valve with a third low dead space connector.

In a second embodiment of the invention, an adapter manifold comprises a three valve block having three diaphragm valves, with the diaphragm side of the first diaphragm valve being juxtaposed to, and having flow communication with, the diaphragm side of the second diaphragm valve and the seat side of the third diaphragm valve, while the seat sides of the first and second diaphragm valves and the diaphragm side of the third diaphragm valve are each connected to low dead space connectors by means of individual conduits.

In a first variant of the second embodiment, the seat sides of all three valves are juxtaposed to, and in flow communication with, each other. In a second variant of the second embodiment, the seat sides of two of the valves and the diaphragm side of the other valve are juxtaposed to, and in flow communication with, each other. In a fourth variant, the diaphragm sides of all three valves are juxtaposed to, and in flow communication with, each other.

It is an advantage of the present invention to shorten the purge cycle of a high purity chemical delivery system. It is a fUrther advantage of the present invention to provide a compact delivery system for a high purity chemical.

It is another advantage of the present invention to reduce capital outlays in high purity chemical delivery systems requiring predetermined purity levels.

It is yet another advantage of the present invention to reduce the connection spaces between valves in a high purity chemical environment.

These and other advantages of the present invention will become apparent from a reading of the following description, and may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Brief Description of Drawings

The drawings constitute a part of this specification and include exemplary embodiments of the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.

Fig. 1 is a cross-sectional view of a portion of an adapter manifold with a dual valve block according to the prior art.

Fig. 2 is a front view of an adapter manifold with a dual valve block according to a first embodiment of the present invention. Fig. 3 is a cross-sectional view of a portion of the embodiment of Fig. 2 illustrating portions of the first and second diaphragm valves.

Fig. 4 is a schematic diagram of a portion of a high purity chemical delivery system comprising the present invention.

Fig. 5 is a front view of an adapter manifold with a three valve block according to a second embodiment of the present invention.

Fig. 6A is a first cross-section view of the embodiment of Fig. 5 illustrating portions of the first and third diaphragm valves.

Fig. 6B is a second cross-section view of the embodiment of Fig. 5 illustrating a portion of the second diaphragm valve.

Modes for Carrying Out the Invention

Detailed descriptions of embodiments of the invention are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, the specific details disclosed herein are not to be interpreted as limiting, but rather as a representative basis for teaching one skilled in the art how to employ the present invention in virtually any detailed system, structure, or manner.

Turning to Fig. 2, there is shown a first embodiment of the invention. An adapter manifold 28 comprises a dual valve block that comprises a first diaphragm valve 30 and a second diaphragm valve 32, wherein each of diaphragm valves 30 and 32 comprises a diaphragm, a seat side and a diaphragm side.

A first low dead space connector 34 detachably connects adapter manifold 28 to a first container suitable for storing the high purity chemical, while a second low dead space connector 36 creates flow communication between adapter manifold 28 and a process tool or a second container during ordinary manufacturing conditions, and between adapter manifold

28 and a source of purge gas or a source of vacuum during a purge cycle. Further, a third low dead space connector (not shown) creates flow communication between adapter manifold 28 and a source of vent or a source of vacuum during the purge cycle. A plurality of conduits connect diaphragm valves 30 and 32 to each other and to the above mentioned low dead space connectors, as described in the following paragraphs.

Examples of low dead space connectors include fittings of the standard VCR type, as well as low obstruction fittings such as Fujikin's UPG gasket fittings or Hy-Tech's Full Bore

002 fittings. Turning now to Fig. 3, there is shown a cross section of the dual valve block. A first conduit 38 connects first low dead space connector 34 to an intermediary conduit 40, which in turn connects a first orifice 42 on the diaphragm side of first diaphragm valve 30 to a. second orifice 44 on the seat side of second diaphragm valve 32.

Further, a second conduit 46 connects sescond low dead space connector 36 to a third orifice 48 on the seat side of first diaphragm 30, and a third conduit 50 connects the third low dead space connector (indicated by reference numeral 58 in Fig. 4) to a fourth orifice 52 on the diaphragm side of second diaphragm valve 32.

The diaphragms of first diaphragm valve 30 and second diaphragm valve 32 are typically disks each having a convex side and a concave side, the concave side being oriented in the direction of the valve seat. These diaphragms are typically made of a flexible material, such as a flexible metal. Further, first diaphragm valve 30 and second diaphragm valve 32 may each be actuated manually, pneumatically, or electrically with a solenoid, the related actuator being connected to the diaphragm of each valve.

First low dead space connector 34, second low dead space connector 36, and third low dead space connector 58 may each be of different designs. For instance, all of the low dead space connectors may be of a standard VCR type, or first low dead space connector 34 may be of a standard VCR design, while second low dead space connector 36 and/or third low dead space connector 58 may be of a low obstruction design. The operation and advantages of adapter manifold 28 may be better understood upon reference to Fig. 4. During ordinary manufacturing conditions, the high purity chemical is delivered from a first container 54 to a process tool or to a second container, exiting container 54 through a container isolation valve 56, which enables or prevents flow communication between container 54 and the rest of the high purity chemical delivery system. Because container isolation valves are known in the art, container isolation valve 56 will not be described in detail here.

The high purity chemical successively flows through adapter manifold 28, entering adapter manifold 28 through first low dead space connector 34 and exiting through second low dead space connector 36. Therefore, the chemical flows through first diaphragm valve 30, which is in an open condition, but not through second diaphragm valve 32, which is maintained in a closed condition.

During an optional initial step of the purge cycle, first diaphragm valve 30 and adapter valve 56 are in an open condition and second diaphragm valve 32 is in a closed condition. Purge gas is blown through second low dead space connector 36 into container 54, purging second conduit 46, a portion of intermediate conduit 40, and first conduit 38.

Thereafter, container isolation valve 56 is closed and second diaphragm valve 32 is opened. Purge gas is then blown through second low dead space connector 36 to a source of vent connected to third low dead space connector 58. Optionally, vacuum may be applied at third low dead space connector 58, in order to increase the flow of the purge gas through adapter manifold with dual valve block 28.

Subsequently, first diaphragm valve 30 and second diaphragm valve 32 are in a closed condition, and vacuum is be applied at second low dead space connector 36, removing any residual chemical from adapter manifold 28, or, under less restrictive purity conditions, providing verification that all chemical has been removed from the seat side of first diaphragm valve 30.

Because all dead pockets have been substantially eliminated from the conduits, the dual valve block of the present invention provides for more efficient and shorter purge cycles than in the prior art. Further, the vacuum step may be omitted other than for verifying that the chemical has been removed, which provides for a purge cycle with essentially only two steps, therefore, for a shorter and more economical purge cycle. If the vacuum step is eliminated, a more compact and less expensive vacuum pump may be employed for the purpose of verifying chemical removal, providing for a less expensive plant construction than in the prior art. Variants of the first embodiment comprise adapter manifolds for high parity chemical delivery systems that comprise different types of dual valve blocks, including dual valve blocks known in the prior art.

For instance, one variant of the present invention comprises an adapter manifold for high purity chemical delivery systems having the dual valve block illustrated in Pig. 1. More specifically, this variant comprises an adapter manifold having a dual valve block with a first diaphragm valve and a second diaphragm valve, wherein the seat sides of the two diaphragm valves are juxtaposed to each other and are connected by a first conduit. A second conduit connects the diaphragm side of the second diaphragm valve to a first low dead space connector, a third conduit further connects the first conduit to the second low dead space connector, and, still further, a fourth conduit connects the diaphragm side of the first diaphragm valve to the third low dead space connector. Within a semiconductor manufacturing facility, the first low dead space connector can be employed to detachably connect the adapter manifold to a container for storing a high purity chemical, while the second low dead space connector can detachably connect the adapter manifold to a process tool or to a second container, and the third low dead space connector can detachably connect the adapter manifold to a source of vent.

Turning now to Fig. 5, there is shown a second embodiment of the invention. An adapter manifold 60 comprises a three valve block having a first diaphragm valve 62, a second diaphragm valve 64 (visible only partially), and a third diaphragm valve 66, the three diaphragm valves being interconnected as explained in the following paragraphs.

A plurality of conduits extends from the three valve block, in order to connect the three valve block to external sources. In particular, a first tube 68 extends from the three valve block and connects first diaphragm valve 62 to a first external source, such as a process tool, a source of pressurized gas, or a source of vacuum. A first low dead space connector 70, for instance, a fitting of the standard VCR type or a low obstruction fittings such as Fujikin's UPG gasket fitting or a Hy-Tech's Full Bore 002 fitting, may be employed to provide a detachable connection between first tube 68 and the first external source; alternatively, first tube 68 may comprise a weld stub. A second tube 72 also extends from the three valve block and connects second diaphragm valve 64 to a second external source, such as a low vapor pressure high purity container. A second low dead space connector may also be employed to provide a detachable connection between second tube 72 and the second external source, or, alternatively, second tube 72 may comprise a weld stub. Additionally, a third tube (not shown) extends from the three valve block assembly and connects third diaphragm valve 66 to a third external source, for instance, a source of vent or vacuum. A third low dead space connector may be further employed to provide a detachable connection between the third tube and the third external source, or, alternatively, the third tube may comprise a weld stub. Turning now to Figs. 6A and 6B, there are shown two different cross-section views of the three valve block 104. More specifically, there is shown in Fig. 6 A a partial cross-section view of three valve block 104 showing first diaphragm valve 62 and of third diaphragm valve 66, and in Fig. 6B a partial cross-section view of three valve block 104 showing second diaphragm valve 64. Each of the three diaphragm valves 62, 64, and 66 comprises a diaphragm, a seat side, and a diaphragm side. The diaphragms of each valve are typically disks made of a flexible material, such as a flexible metal, and have a concave side and a convex side, the concave side engaging the valve seat.

As shown in Figs. 6A-6B, first seat side 74 of first diaphragm valve 62 is connected to the first external source by means of a first conduit 94, while first diaphragm side 76 of first diaphragm valve 62 is juxtaposed to, and has flow communication with, third seat side 78 of third diaphragm valve 66. By reason of its construction, first diaphragm side 76 also has flow communication with the diaphragm side of second diaphragm valve 64.

First seat side 74 and third seat side 78 are connected by first short channel 88, while second short channel 90 provides flow communication between second diaphragm side 96 and first short channel 88 by means of aperture 92.

First diaphragm 82 engages first seat side 74, while second diaphragm 86 engages second seat side 80, and third diaphragm 84 engages third seat side 78. These diaphragms may be actuated manually, pneumatically, or electrically with a solenoid. At the same time, second seat side 80 of second diaphragm valve 64 is connected to the second external source by means of a second conduit 98, while third diaphragm side 100 of third diaphragm valve 66 is connected to the third external source by means of a third conduit 102.

In a first variant of the second embodiment (not shown), first short channel 88 connects first seat side 74 to third seat side 78, while second short channel 90 connects second seat side 80 to first short channel 88. Therefore, in the first variant, each of the seat sides are juxtaposed to, and in flow communication with, each other, while each of the diaphragm sides is connected to an external source by means of individual conduits. In a second variant of the second embodiment (not shown), first short channel 88 connects first diaphragm side 76 to third seat side 78, while second short channel 90 connects second seat side 80 to first short channel 88. Therefore, in the second variant, first diaphragm side 76, second seat side 80, and third seat side 78 are juxtaposed to, and in flow communication with, each other, while first seat side 74, second diaphragm side 96, and third diaphragm side 100 are each connected to an external source by means of individual conduits.

In a third variant of the second embodiment (not shown), first short channel 88 connects first diaphragm side 76 and third diaphragm side 100, while second short channel 90 connects second diaphragm side 96 to first short channel 88. Therefore, in the third variant, all three diaphragm sides are juxtaposed to, and in flow communication with, each other, while each of the seat sides is connected to an external source by means of individual conduits.

While the invention has been described in connection with the above described embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the scope of the invention.

Industrial Applicability The present invention finds industrial applicability in manufacturing plants requiring the transport of high purity chemicals.

The present invention finds particular industrial applicability in semiconductor manufacturing plants, wherein high purity chemicals must be transported from storage containers to process tools.

Claims

CLAIMSWhat is claimed is:

1. An adapter manifold with dual valve block comprising: a first diaphragm valve having a first diaphragm, a first seat side, and a first diaphragm side; and a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side, wherein the first diaphragm side is juxtaposed to, and has flow communication with, the second seat side, wherein a first conduit provides flow communication between the first diaphragm side and the second seat side and a first external source, wherein a second conduit provides flow communication between the first seat side and a second external source, and wherein a third conduit provides flow communication between the second diaphragm side and a third external source.

2. The adapter manifold with dual valve block of claim 1, wherein each of the first and second diaphragm valves has a valve actuator engaged to its diaphragm, the actuator being structured to cause the valve to switch between an open condition and a closed condition.

3. The adapter manifold with dual valve block of claim 1, wherein a first low dead space connector detachably connects the first conduit with the first external source, the first external source being a container for storing a high purity chemical, wherein a second low dead space connector detachably connects the second conduit with the second external source, the second external source being a process tool, a second container for storing the high purity chemical, a source of gas, or a source of vacuum, and wherein a third low dead space connector detachably connects the third conduit with the third external source, the third external source being a source of vent, or a source of vacuum.

4. The adapter manifold with dual valve block of claim 3, wherein the first low dead space connector is of the standard VCR type.

5. The adapter manifold with dual valve block of claim 3, wherein the second low dead space connector is a low obstruction fitting.

6. The adapter manifold with dual valve block of claim 3, wherein the third low dead space connector is a low obstruction fitting.

7. The adapter manifold with dual valve block of claim 3, wherein the first, second, and third low dead space connectors are of the standard VCR type.

8. An adapter manifold with dual valve block comprising: a dual valve block comprising, a first diaphragm valve having a first diaphragm, a first seat side, and a first diaphragm side, and a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side, wherein the first seat side is juxtaposed to, and has flow communication with, the second seat side, wherein a first conduit connects the second diaphragm side with a first low dead space connector, the first low dead space connector detachably connecting the dual valve block with a first external source, the first external source being a container for storing a high purity chemical; wherein a second conduit connects the first and second seat sides with a second low dead space connector, the second low dead space connector detachably connecting the dual valve block with a second external source, the second external source being a process tool, a second container for storing the high purity chemical, a source of gas, or a source of vacuum; and wherein a third conduit connects the first diaphragm side with a third low dead space connector, the third low dead space connector detachably connecting the dual valve block with a third external source, the third external source being a source of vent, or a source of vacuum.

9. An adapter manifold with three valve block assembly comprising: a first diaphragm valve having a first diaphragm, a first seat side, and a first diaphragm side; a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side; and a third diaphragm valve having a third diaphragm, a third seat side and a third diaphragm side, wherein the first diaphragm side is juxtaposed to, and has flow communication with, the second diaphragm side and the third seat side, and wherein a first conduit provides flow communication between the first seat side and a first external source, wherein a second conduit provides flow communication between the second seat side and a second external source, and wherein a third conduit provides flow communication between the third diaphragm side and a third external source.

10. The adapter manifold with three valve block of claim 9, wherein each of the first, second, and third diaphragm valves has a valve actuator engaged to their diaphragm, the actuator being structured to cause the valve to switch between an open and a closed condition.

11. The adapter manifold with three valve block of claim 9, wherein a first low dead space connector detachably connects the first conduit with the first external source, the first external source being a process tool, a secondary container, a source of pressurized gas, or a source of vacuum; wherein a second low dead space connector detachably connects the second conduit with the second external source, the second external source being a primary container, and wherein a third low dead space connector detachably connects the third conduit with the third external source, the third external source being a source of vent.

12. An adapter manifold with three valve block comprising: a first diaphragm valve having a first diaphragm, a first seat side, and a first diaphragm side; a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side; and a third diaphragm valve having a third diaphragm, a third seat side and a third diaphragm side, wherein the first seat side is juxtaposed to, and has flow communication with, the second and third seat sides, and wherein a first conduit provides flow communication between the first diaphragm side and a first external source, wherein a second conduit provides flow communication between the second diaphragm side and a second external source, and wherein a third conduit provides flow communication between the third diaphragm side and a third external source.

13. The adapter manifold with three valve block of claim 12, wherein a first low dead space connector detachably connects the first conduit with the first external source, the first external source being a process tool, a secondary container, a source of pressurized gas, or a source of vacuum; wherein a second low dead space connector detachably connects the second conduit 5 with the second external source, the second external source being a primary container, and wherein a third low dead space connector detachably connects the third conduit with the third external source, the third external source being a source of vent.

14. An adapter manifold with three valve block comprising: a first diaphragm valve having a first diaphragm, a first seat side, and a first [0 diaphragm side; a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side; and a third diaphragm valve having a third diaphragm, a third seat side and a third diaphragm side,

15 wherein the first diaphragm side is juxtaposed to, and has flow communication with, the second and third seat sides, and wherein a first conduit provides flow communication between the first seat side and a first external source, wherein a second conduit provides flow communication between the second 0 diaphragm side and a second external source, and wherein a third conduit provides flow communication between the third diaphragm side and a third external source.

15. The adapter manifold with three valve block of claim 14, wherein a first low dead space connector detachably connects the first conduit with 5 the first external source, the first external source being a process tool, a secondary container, a source of pressurized gas, or a source of vacuum; wherein a second low dead space connector detachably connects the second conduit with the second external source, the second external source being a primary container, and wherein a third low dead space connector detachably connects the third conduit with 0 the third external source, the third external source being a source of vent.

16. An adapter manifold with three valve block comprising: a first diaphragm valve having a first diaphragm, a first seat side, and a first diaphragm side; a second diaphragm valve having a second diaphragm, a second seat side, and a second diaphragm side; and a third diaphragm valve having a third diaphragm, a third seat side and a third diaphragm side,

5 wherein the first diaphragm side is j uxtaposed to, and has flow communication with, the second and third diaphragm sides, and wherein a first conduit provides flow communication between the first seat side and a first external source, wherein a second conduit provides flow communication between the second seat side 0 and a second external source, and wherein a third conduit provides flow communication between the third seat side and a third external source.

17. The three valve block assembly of claim 15, wherein a first low dead space connector detachably connects the first conduit with 5 the first external source, the first external source being a process tool, a secondary container, a source of pressurized gas, or a source of vacuum; wherein a second low dead space connector detachably connects the second conduit with the second external source, the second external source being a primary container, and wherein a third low dead space connector detachably connects the third conduit with :0 the third external source, the third external source being a source of vent.