Background
ArcFM Cathodic Protection (CP) tracing for gas and water networks relies on coded value domains to determine whether a pipe or device should be considered conductive – and thus traceable – or not. Key among these are these fields. (For the priority of what happens when one field indicates traceable and another indicates non-traceable see the ArcFM Resources site.)
| Field | Domain | Values |
| BondedIndicator | Yes No Indicator | “Y” = traceable, “N” = non-traceable |
| InsulatedIndicator | Yes No Indicator | “Y” = non-traceable, “N” = traceable |
| CPSystemStatus | CP System Status | [0] “Closed” = traceable , [1] “Open” = non-traceable |
| Material | <Varies> | <Varies> |
As shown in the table above, the Material field has the ability to vary from class to class – and that’s the topic of this post.
The Problem
Material of course requires more than a Yes/No or Closed/Open domain, so the way ArcFM traces are informed of whether the material should be considered conductive or not requires another method. That method is another domain named “Material Conductivity.” You can use this domain to hold all material code values and a conductive/non-conductive indicator for all gas network classes that have a material field.
The standard Minerville model has a few values in this table for the most common material types, but your implementation may have extended material domains for different feature classes. Here’s the Minerville version of this domain (a Description value of 1 means conductive and 0 means non-conductive) with columns added to show the associated classes and domain values.
| Domain Values | |||
| Code | Description | Applies to Class(es) | Subtype / Domain Value |
| 1 | 1 | DistributionMain | Subtype [1] “Bare Steel” |
| 2 | 0 | DistributionMain | Subtype [2] “Cast Iron” |
| 3 | 1 | DistributionMain | Subtype [3] “Coated Steel” |
| 4 | 1 | DistributionMain | Subtype [4] “Copper” |
| 5 | 0 | DistributionMain | Subtype [5] “Plastic” |
| BS | 1 | Service | Gas Pipe Service Material [BS] “Bare Steel” |
| CI | 0 | GasValve | Gas Valve Material [CI] “Cast Iron” |
| CI | 0 | Service | Gas Pipe Service Material [CI] “Cast Iron” |
| CS | 1 | Service | Gas Pipe Service Material [CS] “Coated Steel” |
| CU | 1 | Service | Gas Pipe Service Material [CU] “Copper” |
| PL | 0 | GasValve | Gas Valve Material [PL] “Plastic” |
| PL | 0 | NonControllableFitting | Gas Fitting Material [PL] “Plastic” |
| PL | 0 | ControllableFItting | Gas Fitting Material [PL] “Plastic” |
| PL | 0 | Service | Gas Pipe Service Material [PL] “Plastic” |
In your implementation chances are good that you will account for more material types than are present in Minerville — possibly different types of plastic, or hybrid compounds or ductile iron or wrought iron, or any number of other materials of equipment used to convey gas and water.
Normally values in one domain are completely independent, so if you used “BS” to indicate Bare Steel in your valve material domain and “BARE” to indicate Bare Steel in your fitting domain it’s no big deal. However, since all these values will be combined in a single domain for material conductivity you’ll want to take care to avoid overlaps and ensure consistency.
Your Solution Approach
As you’re extending the various material domains it might help to maintain a master value list, something like the following:
Material Field Domains
| Material | Class | Domain | Value |
| Bare Steel | |||
| DistributionMain | Subtype | 1 | |
| Service | Gas Service Material | BS | |
| GasValve | Gas Valve Material | BS | |
| Fitting | Gas Fitting Material | BS | |
| Plastic | DistributionMain | Subtype | 5 |
| Service | Gas Service Material | PL | |
| GasValve | Gas Valve Material | PL | |
| Fitting | Gas Valve Material | PL | |
| … and so forth | |||
This will help ensure you’re using consistent values that won’t get confused when you’re building out your Material Conductivity domain. Goodness knows that keeping track of CP system extents is challenging enough without adding confusion about what materials are conductive and what are not.
