Create Branch

The Create Branch window allows you to create a branch element.

In the Name box, input the name of the new Branch.

The Slope Ref specifies the slope reference attribute (the default is none). To change the slope reference attribute, select a slope reference from the Slope Ref: drop-down list.

By default the specification selected in Default Pipe Specification will be used but you can select an alternative specification, click Specifications. you can now change the Default Specifications, for further information, refer to Default Pipe Specification.

Click Attributes, the Branch Attributes window is displayed, you can view or modify the attributes of the Branch element

The way in what the head or tail is connected or positioned can be changed by selecting from a choice of options in the Head/Tail Setting drop-down list:

• Connect - Select Connect and click OK, the Connect Branch window is displayed:

You are required to specify if it is the Head or Tail of the branch which is to be connected, and then to what component the head or tail is to connect to from the choice of options in the To drop-down list. or click CE.

Click Apply to save the changes and close the Connect Branch window, you are prompted to select the head and then the tail of the branch in the 3D graphical view.

Click Reset to discard any changes or Dismiss to discard the changes and close the Connect Branch window.

• Explicit - Select Explicit and click OK, the Branch at Explicit Position window is displayed:

  

You are required to specify the position and orientation for the head and tail in the Position: part of the Branch at Explicit Position window using the generic positioning options.

To change the bore size of the head or tail, select a bore size from the Bore drop-down list.

In Direction enter the leave direction of the head or tail.

The type of connection to be made at the head or tail (for example: flange, gasket) can be changed by selecting from a choice of options in the Connection drop-down list.

The Slope Ref specifies the slope reference attribute (the default is none). To change the slope reference attribute, select a slope reference from the Slope Ref: drop-down list.

Click Apply to save the changes and close the Branch at Explicit Position window, you are prompted to select the head and then the tail of the branch in the 3D graphical view.

Click Reset to discard any changes or Dismiss to discard the changes and close the Branch at Explicit Position window.

• None - Select None - the head and tail are unset (not connected or positioned).

Routing Pipes

You must now add the pipes to the Pipe Router window, and then route the pipes, Pipes can be added individually or in groups.

By default, the Pipe Router routes pipes in the order in which they are added to the Pipe Router window. The routing order can have an effect on the route taken by pipes. Pipe Router routes the selected pipes, adding elbows, gaskets and flanges, as required.

When a pipe is added to Pipe Router, it is given a head and tail work-point. These are the points where a route begins and ends. Pipe Router positions work-points at a distance from the branch head or tail which allows for any connection components that are required.

For example, if the head of a branch is a flanged nozzle, then Pipe Router will automatically add a gasket and a flange. Pipe Router will then begin routing the pipe from the end of the flange.

How Pipe Router Finds a Route

The Pipe Router creates a route using an algorithm which minimizes material cost while avoiding clashes with other objects. The algorithm has three modes of operation, described as Level 1, Level 2 and Level 3 modes. Pipe Router first searches for a route using Level 1 mode. If no clash-free Level 1 route is found, a search is made using Level 2 mode, and if no Level 2 route is found Level 3 mode is used.

Level One Mode

In level one mode, Pipe Router searches for an orthogonal route between the head and tail work-points of a pipe, using the minimum number of bends or elbows. Lever One routes (Box 3) shows examples of the routes available in level one mode.

An example of a Level One route displays a level one route in which the head work-point is facing up.

Level Two Mode

If all first level routes are blocked, Pipe Router will attempt to find second level routes. In second level mode, Pipe Router will withdraw the route into the box by a distance which enables the pipe to bypass the obstruction. Pipe Router then attempts the same routing patterns as those used in level one mode. An example of a level two route is shown below.

Level Three Mode

If Pipe Router cannot find a clash-free route using first and second level routes, it will attempt to find a third level route. In third level mode, Pipe Router extends the box outwards until it bypasses the obstruction and then attempts to route the pipe using level one routing principles. An example of a level three route is shown below.

Adding Components to a Route

Once Pipe Router has worked out a route, it constructs the Branch by adding whatever Elbows (or Bends) are needed.

Note:
To be efficient, Pipe Router imposes a low upper limit on the number of Elbows it will add to a Branch: it does not attempt to be a maze solver.

You can specify components in a Branch before routing, for example by importing a P&ID file as described in Import a P&ID File. You can also modify a routed Branch by adding other components, for example, Valves or Instruments, by selecting Modify > Branch from the main menu and creating the components in the normal way.

Only the principal piping components need to be added. Pipe Router will add Flanges, Gaskets, lap joint stub ends and Welds as necessary, using the COCO (Connection Compatibility) tables to create the correct types.

Components can be locked into a given position, in which case they will not be moved, even if the Branch is re-routed.

Insertion of Reducers at Bore Changes

Before Pipe Router positions any components on a Branch, it checks the Branch to see if it contains any components whose bore is different from the preceding component. If one is found, then by default the Pipe Router will select the first suitable Reducer that it finds in the catalogue, regardless of whether it is concentric or eccentric.

You can set rules to specify whether concentric or eccentric Reducers are used.

Note:
Pipe Router treats bores being equal if they are the same within 5mm.

How Pipe Router Routes to Free Tails

If a Branch has a free Tail, that is, if the Tail is not connected to another Branch or you have not specifically defined the Tail position, Pipe Router will automatically position the Tail once it has positioned all of the components in the Branch and applied all constraints.

If this fails, for example, because there is a clash or a component positioning rule cannot be satisfied, then it will introduce an Elbow after the constraint, before the first component. Pipe Router will then position the elbow in a direction that results in a clash-free route, and which satisfies component positioning and orientation rules.

If the Branch does not have any constraints, the position of the Tail depends on the position and orientation of the Branch Head. Often, this may be a Tee.

Tail direction: The TDIR attribute for a free tail is never set if the last constraint is a plane or a rack. In all other cases, TDIR is taken from the direction of the last component.

How the Pipe Router Positions Tees

Pipe Router checks each Branch for connections to other Branches, that is it looks for Tees or other components which have a CREF or CRFA attribute set.

If the Branch which connects to the Tee has a free Tail, then the Tee is treated the same as any other component.

In all other cases, the Tee will influence the route taken by the original Branch. In general, Pipe Router will select the closest route to any constraints in the connecting Branch. If there are none, then it will select the route closest to the other end of the connecting Branch.

Tees which can be balanced will then be positioned.

Where a Branch contains more than one Tee, the first Tee in the Branch will influence the route taken. Pipe Router will position any subsequent Tees as close as possible to the next constraint, or the other end of the connecting branch.

You can control the position of a Tee by locking it in position, or by constraining the route, using a routing point.

Balanced Tees

Pipe Router will try to position a Tee to achieve balanced flow.

The Tee must be symmetric about a plane through P-arrive. The Pipe Router will change the arrive p-point to achieve this if the bores on the p-points are equal. It will then check the leave-bore and connect-bore. If the bores are equal then Pipe Router will assume that the Tee is T-shaped.

The Tail directions of /B1 and /B2 must either be equal and not in the axial direction between the Tail positions of the branches or opposite and in the axial direction between the Tail positions of the branches:

There must be no locked components on branch /B2, nor any after the Tee on branch /B1.

If there are multiway components in the Branches after the Tee, the Branches connected to them:

• Must have equivalent lists of component specifications,

• Must be unconstrained

• Must have free tails

The Tail positions of /B1 and /B2 must be equal in two of the three orthogonal co-ordinates:

The specifications of the positionable components after the Tee on /B1 must be the same as the specifications of the components on branch /B2.

The Tee will be positioned so that:

• The Tee is clash-free

• There is enough room for all components between the Tee and the end of the Branch

• The position does not result in a route to the Tee with an elbow close to the Tee.

If any of these conditions are not satisfied, Pipe Router will try moving the Tee back along the arrive direction (or forward along the leave direction).

Covered Nozzles

When the Pipe Router is routing a Branch there may be several others waiting to be routed. The best route for the current Branch may take the Pipe straight in front of other Nozzles, which is most likely to happen when routing from a line of Vessels. It can be avoided by:

Make sure the Nozzles or Equipment owning them have obstruction volumes extending beyond their Nozzles which prevents other Pipes crossing in front of the Nozzle. The Branch connected to the Nozzle will ignore this clash and successfully route onto the Nozzle.

Note:
The obstruction volumes should be defined in the Catalogue: defining them in Design may result in less satisfactory routes.

Constraining a Route

Except in very simple cases, you will need to give Pipe Router more information about the route required to achieve a satisfactory route. You can constrain a route using the following:

• Locked components

• Routing Points

• Routing Rules

• Routing Planes

• Pipe Racks

These constraints are described briefly in the following sections, and described in detail in later sections.

Locked Components

A locked component is a component whose position has been fixed before routing takes place. Pipe Router will route the Branch through the component. Locked components can be used to manually modify the route taken.

In cluttered areas, Pipe Router may not be able to find a clash-free route, in which case it will put in the simplest clashing route and inform you about the clash. You will then need to modify the route to obtain a clash-free route, by moving components away from clashes, locking them and re-routing. Both principal Piping components and router-created components (for example, Elbows), can be moved and locked.

Routing Rules

One of the principal features of Pipe Router is its built-in rule engine. You can use routing rules to control the selection, position and orientation of piping components, and to control how pipes use routing planes and pipe racks. For further information about using Rules, see Routing Rules.

For information about creating your own rules, refer to Automatic Pipe Routing Administration.

Routing Points

Routing Points are points through which a pipe must pass. You can specify the position of a routing point, and the direction in which a pipe arrives at and leaves a routing point. For further information, refer to Create and Use Routing Points.

Routing Planes

Routing planes are orthogonal planes which attract pipes to them and then guide the pipes in the direction of the plane. Routing planes are useful, for example, where you want to group pipes together, perhaps along a wall or ceiling. For further information, refer to Create and Use Routing Planes.

Pipe Racks

In Pipe Router, a pipe rack is composed of a group of routing planes which enables you to model the route used on a physical pipe rack. There are two ways in which you can create a pipe rack. You can create pipe racks on existing steelwork structures or model them simply as a group of planes.

You may find the second method useful when you are working on a conceptual design and do not want to spend time creating steelwork structures. Once a pipe rack has been created, you can use routing rule to specify how different sorts of pipe run on the rack. For further information, refer to Create and Use Pipe Racks.

Checking the Status of a Branch

Once the pipe(s) have been routed, you can check the status of the branch, by selecting Display > Status Summary from the Pipe Router window. The Status Summary window is displayed, showing that two Branches have been routed successfully.

Note:
Update and Dismiss at the bottom of the Pipe Router Status Summary window can be used to update the report file or close the Pipe Router Status Summary window.

Changing the Order in which Pipes are Routed

Pipe Router routes pipes in the order in which they are added to the Pipe Router window. However you may need to change the routing order of particular pipes to ensure that Pipe Router routes the most expensive pipes first. Or if you are working with pipes that are in close proximity to one another or where pipes cross paths.

You can change the routing order, by selecting from a choice of options in the Modify > Routing Order > from the Pipe Router window.

• Auto - Automatically reorders branches according to routing dependencies, that is, if a pipe is dependent on another pipe, then that pipe will be routed first. Select this option, for example, after you reorder by bore.

  Note:
  Option only affects piping networks: It will have no effect on unconnected Pipes.

• Manual > Pipes - You can manually specify the order in which the Pipe Router routes each pipe, using the Pipe Router - Reorder Pipes window.

• Manual > Branches - You can manually specify the order in which the Pipe Router routes each branch, using the Pipe Router - Reorder Branches window.

• By Attribute - You can reorder pipes according to particular attributes in ascending or descending order, using the Reorder by Attribute window.

  

To reorder pipes according to their specification, select Group by specification check box, which reorders the pipes so that they are displayed in alphabetical order of their specification names, for example, all pipes which use the specification A150, followed by all pipes which use the specification B150, and so on. You can use this option in conjunction with the attribute radio buttons.

For example, reorder pipes so that all Pipe Router displays all pipes which use the specification A150 in descending order of their head bore, followed by all B150 specification pipes.