Manifold trailer with multiple articulating arm assemblies

1. A manifold trailer which comprises at least one main line having a plurality of discharge connectors and a plurality of articulating arm assemblies which are each connected to a corresponding discharge connector, each arm assembly comprising:

a connector member which includes at least an inlet port, an outlet port and a third port which is located generally opposite the outlet port and is closed by a removable plug member;

an articulating conduit assembly which comprises a first end that is connected to the inlet port; and

a riser swivel which is connected to the outlet port;

wherein a second end of the conduit assembly is connectable to a pumping unit to thereby fluidly connect the pumping unit to the main line.

2. The manifold trailer of claim 1 , wherein the third port is positioned vertically above the inlet and outlet ports.

3. The manifold trailer of claim 2 , wherein the third port is positioned vertically above the conduit assembly when the second end is connected to the pumping unit.

4. The manifold trailer of claim 1 , further comprising a choke insert which is positioned in the outlet port and is removable through the third port.

5. The manifold trailer of claim 4 , wherein the choke insert is positioned in a counterbore formed in the outlet port.

6. The manifold trailer of claim 4 , wherein the choke insert is supported on a seal assembly which is positioned between the connector member and the riser swivel.

7. The manifold trailer of claim 6 , wherein the seal assembly comprises a bushing which projects radially into the outlet port and on which the choke insert is supported.

8. The manifold trailer of claim 4 , wherein the choke insert extends through the third port to the plug member.

9. The manifold trailer of claim 8 , wherein the choke insert includes a transverse pull bar which is located proximate the plug member.

10. The combination manifold trailer of claim 8 , wherein the choke insert is connected to the plug member.

11. The combination manifold trailer of claim 8 , wherein the choke insert includes at least one inlet opening and the arm assembly further comprises means for aligning the inlet opening with the inlet port.

12. The combination manifold trailer of claim 11 , wherein the aligning means comprises an alignment pin which is received in opposing holes in the plug member and the connector member when the inlet opening is aligned with the inlet port.

13. The manifold trailer of claim 11 , wherein the connector member comprises a fourth port which is located generally opposite the inlet port and the aligning means comprises a locator pin which is positioned in the fourth port and which includes an axial projection that is received in a corresponding hole in the choke insert when the inlet opening is aligned with the inlet port.

14. The manifold trailer of claim 8 , wherein the plug member comprises a blind nut and the choke insert comprises a radial flange which is trapped between the blind nut and an adjacent portion of the connector member to thereby secure the choke insert within the connector member.

15. The manifold trailer of claim 14 , further comprising a first seal which is positioned between the flange and the blind nut and a second seal which is positioned between the flange and the adjacent portion of the connector member.

16. The manifold trailer of claim 8 , wherein the plug member comprises a blind plug which extends into the choke insert and is secured to the connector member by a nut.

17. The manifold trailer of claim 1 , wherein the connector member comprises a fourth port which is located generally opposite the inlet port and is closed by a second removable plug member.

18. The manifold trader of claim 17 , wherein the connector member is configured such that each of the inlet port and the fourth port is connectable to the conduit assembly.

19. The manifold trailer of claim 17 , further comprising a choke insert which is positioned in the inlet port and is removable through the fourth port.

20. The manifold trailer of claim 19 , wherein the choke insert is positioned in a counterbore formed in the inlet port.

21. The manifold trailer of claim 19 , wherein the choke insert is supported against a seal assembly which is positioned between the connector member and the conduit assembly.

22. The combination manifold trailer of claim 21 , wherein the seal assembly comprises a bushing which projects radially into the inlet port and against which the choke insert is supported.

23. The manifold trailer of claim 19 , wherein the choke insert extends through the fourth port to the second plug member.

24. The manifold trailer of claim 23 , wherein the choke insert includes a transverse pull bar which is located proximate the second plug member.

25. The manifold trailer of claim 23 , wherein the choke insert is connected to the second plug member.

26. The manifold trailer of claim 23 , wherein the second plug member comprises a blind nut and the choke insert comprises a radial flange which is trapped between the blind nut and an adjacent portion of the connector member to thereby secure the choke insert within the connector member.

27. The manifold trailer of claim 26 , further comprising a first seal which is positioned between the flange and the blind nut and a second seal which is positioned between the flange and the adjacent portion of the connector member.

28. The combination manifold trailer of claim 23 , wherein the second plug member comprises a blind plug which extends into the choke insert and is secured to the connector member by a nut.

29. The manifold trailer of claim 4 , wherein:

the choke insert includes a choke orifice which comprises an exit opening diameter at an end of the choke orifice adjacent the riser swivel;

the riser swivel includes a male swivel part which comprises a male swivel bore and a female swivel part which comprises a female swivel bore; and

the diameter of at least one of the male swivel bore and the female swivel bore increases from a first diameter approximately equal to the exit opening diameter to a second, larger diameter to thereby create a pressure drop in a fluid flowing through the riser swivel.

30. The manifold trailer of claim 4 , wherein:

the choke insert includes a choke orifice which comprises an exit opening diameter at an end of the choke orifice adjacent the riser swivel;

the riser swivel includes a male swivel part which comprises a male swivel bore and a female swivel part which comprises a female swivel bore;

the female swivel part is located adjacent the choke insert;

the diameter of the female swivel bore increases from a first diameter approximately equal to the exit opening diameter to a second, larger diameter; and

the diameter of the male swivel bore is approximately equal to the second diameter.

31. The manifold trailer of claim 4 , wherein:

the choke insert includes a choke orifice which comprises an exit opening diameter at an end of the choke orifice adjacent the riser swivel;

the riser swivel includes a male swivel part which comprises a male swivel bore and a female swivel part which comprises a female swivel bore;

the female swivel part is located adjacent the choke insert;

the diameter of the female swivel bore is approximately equal to the exit opening diameter; and

the diameter of the male swivel bore increases from a first diameter approximately equal to the exit opening diameter to a second, larger diameter.

32. The manifold trader of claim 4 , wherein the riser swivel is connected to an isolation valve which in turn is connected to the discharge connector.

33. The combination manifold trailer of claim 32 , wherein:

the choke insert includes a choke orifice which comprises an exit opening diameter at an end of the choke orifice adjacent the riser swivel;

the riser swivel includes a male swivel part which comprises a male swivel bore and a female swivel part which comprises a female swivel bore;

the diameter of the male swivel bore is approximately equal to the exit opening diameter;

the diameter of the female swivel bore is approximately equal to the exit opening diameter; and

the isolation valve includes a valve bore which comprises a diameter that increases from a first diameter approximately equal to the exit opening diameter to a second, larger diameter.

34. The manifold trailer of claim 32 , wherein:

the choke insert includes a choke orifice which comprises an exit opening diameter at an end of the choke orifice adjacent the riser swivel;

the isolation valve includes a valve bore and a closure member which is positioned across the valve bore;

the valve bore comprises a diameter which is larger than the exit opening diameter; and

the closure member includes a closure member bore which comprises an orifice having a diameter which is approximately equal to the exit opening diameter.