Managing Valves in EPCM Projects Part II: More Challenges

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ACTUATOR SUPPLIER SELECTION STRATEGY

Generally, there are two ways of selecting actuator manufacturers. The first way is to select directly from the end-user-approved vendor list. In this case, the number of actuator suppliers may be limited to two or three based on different types of actuation (e.g., electrical, pneumatic, hydraulic). The other approach is to authorize valve suppliers to select suitable actuator suppliers from the approved vendor list of the client. This approach has the advantage of facilitating the communication and coordination between the valve and actuator manufacturers. However, this way may lead to selecting more and more varied actuator suppliers for the project.

ORDERING SPECIAL VALVES

Special valves, for the purposes of this article, are large-size and high-pressure class valves with special designs. For example, oil export pipeline valves could be categorized as special. These valves (Figure 1) are at high risk of being delayed during procurement. They are categorized as long lead items; for example, there may be a one-and-a-half-year duration from the time the valves are ordered until they are delivered to the site. The complexity of these valves can be intensified if, for example, they are top entry and double isolation and bleed designs, if the pup and transition pieces are welded, if they will see a high frequency of pigging, if they face special transportation issues or if they have qualification test requirements. The number of sub-suppliers for these special valves is high, which means constant monitoring and expediting.

MULTIPLE PROJECT TEAM LOCATIONS

Some projects may be handled by a team that comes from different locations (e.g. countries) because of company policy or other reasons. Because they don’t know each other, this makes it especially difficult to build the team. Also, different locations mean differences in culture, systems, work styles and values. This makes such project teams in need of a high level of integrity management and constant communication.

ORDERING VALVES FROM DISTRIBUTORS OR OTHER SUPPLIERS

Distributors act as middle points between valve manufacturers and EPC contractors and clients. Although suppliers can facilitate communication between these two parties, they also can add unnecessary communications and bureaucracy to projects. Distributors neither generate documents nor produce any valves so they rely on valve manufacturers for providing details of engineering concerns and sometimes concerns related to scheduling of the documents and products. For some projects, direct communication between the client/EPC contractor and the valve manufacturer makes communication faster, more accurate and more efficient.

LACK OF VALVE MANUFACTURER CAPACITY

Valve manufacturers are involved in many orders with different clients so they can lose focus on the valves ordered by one particular end user. Alternatively, the quantities of the valves might be high enough that a specific valve manufacturer may not have enough machining equipment, test bench capability or workers available. Thus, the production capacity, as well as the engineering, procurement and manufacturing scheduling of the valve manufacturers, should be checked before purchase orders are made. In some cases, the selected valve manufacturers might subcontract part or all of the work to other manufacturers, which increases the complexity and speed of valve supply within projects.

EARLY CONSTRUCTION SITE NEED DATES

Normally, larger valves have earlier site need dates because construction takes place on the larger lines before the smaller ones. Larger valves normally have longer procurement and delivery times as well. The requirement for a site need date could be stricter if the valve is weld-end rather than a flanged connection. Pipeline butt-weld-ended valves, which are connected to the line through pup pieces, may be extended through the pup pieces to facilitate welding at the construction yard. However, this extension can increase valve fabrication time as well as procurement time. Figure 2 illustrates a 38-inch, Class 1500 installed on the oil export line with an emergency shutdown function. The pup piece on the right side of the valve has been extended to be welded directly to the DNV-code designed pipeline, which puts more risk to the valve fabrication and procurement. The alternative solution is to use a short-length pup piece on the valve and weld a pup piece between the valve pup and DNV-coded pipeline, which creates more construction work.

LATE-STAGE VALVE FAILURES AND PROBLEMS

Some valve problems and failures are discovered at a late stage at the construction site, which causes delays in construction work. Many issues can occur such as a wrong direction of the actuator on the valve or insufficient clearance for installing the valves’ mating-flange fasteners (Figure 3), etc. Such problems normally occur for 4-inch sizes and smaller, full-bore ball valves as well as through-conduit gate valves, where there is not much space between the mating flange body and body piece flange. In some cases, the valves should be returned to the valve supplier for further machining on the body end flanges, which has a severe impact on the construction work schedule. The butterfly valve installation discussed in Part I and illustrated in Figure 3 of Part I is an example of a valve problem during installation.

ORDERING VALVES WITH EXTRA OPTIONS

Some of the ordered valves will have added options such as coatings, stem extensions because of insulation-friendly design, partially or fully Inconel 625 (applicable for carbon steel body valves) and more. Adding these options increases the variety within the project. For example, eight full-bore ball valves of 6 inches in Class 300 in 22 Cr duplex material might remain uncoated. However, a project may call for two other ball valves with the same specification that are insulated and coated to avoid corrosion under the insulation. These valves would be differentiated from the other eight only by coating requirements.

ECONOMIC AND POLITICAL SANCTIONS

Economic and political sanctions negatively impact equipment procurement in EPC projects in ways such as limiting the numbers of potential valve suppliers or making a situation more difficult for the company involved in purchasing. For example, a valve supplier might ask payment in whole for the contract from the purchasing company at the beginning of the project, but the policy from the supplier might be to cover possible risks associated with cooperation or export of equipment or facilities to a sanctioned country.

CONCLUSION

As Parts I and II of this article show, there are many valve-related considerations in EPCM projects. Some of these can be tracked and guided through tools such as piping and instrument diagrams. The important point to remember is that, in the end, knowing the challenges allows those who supply and make the equipment to reach the ultimate goal: satisfied end users.

To read Part I, see VALVE Magazine’s Fall edition.

Karan Sotoodeh is a lead/senior valve and actuator engineer for Baker Hughes.