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Get Acrobat Reader You will need Acrobat Reader to view pdf Joint Reduction Technologies
Life Cycle Cost Estimating

Many specifiers of piping systems limit their economic analysis to piping material costs only, because they are relatively simple to estimate. Yet this approach creates some pitfalls when selecting either an installation of conventional flanged plastic-lined piping (PLP) or an installation that fully incorporates Resistoflex's Joint Reduction Technologies (JRT), consisting of CONQUEST® flangeless connections and MULTI-AXIS® precision bent piping. An evaluation that considers only the cost of pipe, fittings, flanges and connectors may result in specification of a system with the higher life cycle cost.

Life Cycle Cost Considers All Cost Factors

Life cycle cost (LCC) analysis includes all costs of system ownership and permits selection of the less expensive system. Costs can be divided into the following categories:
  • Initial acquisition costs
  • Initial acquisition labor
  • Operating and maintenance costs
  • Costs associated with flange leaks
When deciding to utilize JRT, it's often helpful to perform the evaluation based on the LCC of current practice (i.e., the use of flanged PLP) and then consider which costs would change if the system were designed and installed using the various Joint Reduction Technologies. Different alternatives can be evaluated with the judicious use of JRT and elimination of many, but not all, flanged connections resulting in the most economical PLP installation.

Cost Elements to Consider When Evaluating JRT vs. Conventional PLP

  • Initial Acquisition Costs
- Pipe, fittings, flanges, venting & locking collars and CONQUEST® connectors. These are the items that are purchased from the supplier of PLP. Pipe can be supplied already flanged, or spooled, ready for installation. If the pipe will be fabricated on-site, then a sufficient number of flanges and/or CONQUEST® connectors should be purchased. Don't overlook venting collars for PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxy) lined pipe if flanged pipe ends will be fabricated on-site. These collars are not needed if the pipe is joined with a CONQUEST® flangeless connection.

   - Nuts, bolts or studs needed to join flanged connections.

   - Flange protectors or spray shields. Many corporate or government regulations require that flanged connections be covered or protected so that if a leak occurs, it is either contained or flows in a controlled, predictable pattern instead of spraying at the flanged connection.

- Registration of flanged connections in a corporate database. Often the location of a flanged connection must be noted in records so that its location, maintenance and inspection can be reported. One common technique is to attach a bar code label to the flanged connection, input location and chemical service information into a database. Registration is essential if the service is covered by the 1990 Clean Air Act Amendments (CAAA) or other similar laws governing chemical processes. Many companies register all flanged connections in critical or hazardous services, even if the service isn't currently included in regulations. This is often done either for safety reasons or in anticipation of changes in regulations. Registration usually occurs at the time of installation and is in additional to the recurrent costs of periodic inspection.

- Items that are less costly when flanged connections are eliminated because the piping system is lighter in weight and has a more streamlined profile. These could includes:

  • number and type of hangers
  • support structure
  • diameter or configuration of insulation
  • complexity of heat tracing around connections
- Diameter of the piping system and size of pumps. Don't overlook the improved flow characteristics of JRT, especially of MULTI-AXIS precision bent piping. The 3-D bends of MULTI-AXIS create less pressure drop than the standard 1.5-D bends of conventional PLP. It may be possible to specify a smaller diameter piping system and/or smaller pumps if JRT is specified instead of conventional PLP.
  • Initial Acquisition Labor
- Design and design review. The cost of specifying, ordering and receiving materials can be reduced if the piping is bought as bulk quantities of unflanged, standard length pipe instead of numerous flanged spools with different custom lengths. Also the material acquisition costs for some items (like nuts, bolts, studs, flange protectors and spray shields) are reduced in direct portion to the number of flanged connections eliminated by the use of JRT.

- Field fabrication of custom length pipe. The process of PLP custom spool fabrication includes cutting and threading the pipe, installing and aligning the flange, installing the venting or locking collar, heating the plastic stub, flaring the plastic face, cooling and removing the flaring die and installing a protective wooden cover over the flared face. This process can be time-consuming and quality difficult to control if performed on-site by personnel who fabricate PLP on an infrequent basis. Often custom spools are fabricated at the factory or by nearby stocking distributors who have fully equipped shops and certified personnel that fabricate PLP routinely. If conventional PLP is fabricated at the factory or by a distributor, then the cost will be part of the purchase price quoted by the supplier of the fabricated pipe. Understandably, flanged and fabricated spools are more expensive than plain-end PLP.

- Cost of installation. This includes the cost of installing the piping system and the associated nuts, bolts, studs, flange protectors and spray shields with conventional PLP or the cost of fabricating a CONQUEST® connection when the method is used to create a joint.

- Miscellaneous labor cost savings. Be sure to include labor cost savings if the use of lighter weight, streamlined JRT piping permits a reduction in the number of hangers and supports and if the elimination of flanged connections speeds up the installation of insulation and heat tracing. Also, the time required for painting can be reduced when flanged connections are eliminated. If installation time is reduced, then it's often possible to reduce the time required for rental or recharge of equipment like man-lifts.

- Start-up costs. This includes the time to hydrotest the piping system and perform the recommended retorquing of bolts after 24 hours of operation. When flanged connections are eliminated, the start-up time can be substantially reduced. This means that the system is operational sooner and the process is out of commission for a shorter period of time.

Operating and maintenance costs

- Monitoring and associated paperwork. Government or corporate regulations may require the periodic monitoring of flanged connection for leaks and records of that monitoring activity. If a service is listed in the 1990 CAAA, then the connection must be "sniffed" for fugitive emissions and detailed records maintained for submittal to the government. The monitoring frequency ranges from every six months to biannually, depending upon the service and history of the site. Even if regulations don't require monitoring, it's still good chemical plant operations practice to visually inspect flanged connections periodically for signs of leaks or emissions.

- Periodic retorquing of flange bolts. It's common for flange bolt torques to be checked and bolts tightened, if needed, on a periodic basis. Often this is done semi-annually or annually depending upon the thermal cycling history of the piping. This retorquing isn't needed when flanged connections are eliminated through installation of JRT.

- Cleaning costs. Consider the cost difference in batch-to-batch cleaning of conventional PLP vs. JRT. In some batch processes this can be a savings, particularly when directional changes in the piping are created with MULTI-AXIS piping instead of with conventional flanged elbows, which have a discontinuity or crevice at the flanged connection.

Costs associated with flanged leaks

- Unused capacity. Consider the likelihood of plant outages due to flange leaks and the cost of production that is lost when the plant isn't operating.
- Out-of-spec product. Flange leaks can create a sudden and unexpected plant outage resulting in the production of out-of-spec product.
- Safety issues. The "cost" is difficult to estimate but can be a tangible concern for some chemical services and/or some piping system locations. This could include direct injury to workers and passers-by and indirect issues such as evacuation of the process site and adjacent areas.
- Reporting requirements. Government or corporate regulations can require lengthy and time-consuming reports and investigations in the event of flange leaks. The direct and indirect costs of these reports shouldn't be overlooked.

Example of Life Cycle Cost Estimating Analysis

Consider a piping system that was recently installed with extensive use of JRT. The system consists of 2-in diameter (50 mm N.B.) PVDF-lined piping that was installed in an existing, overhead pipe rack to replace a conventional PLP system that had reached the end of its useful life of several decades. The conventional system consists of 670 ft (204 m) of piping, ten directional changes for routing the thermal expansion purposes and two tees installed as "stand-pipes" to reduce the effect of water hammer. By specifying JRT, all the flange connections, except for the first and last connections. In JRT, the system consists of 620 ft of straight-run piping, three pieces of MULTI-AXIS® precision-bent piping, two CONQUEST® flangeless tees and thirty-seven CONQUEST® connections. The system is depicted in the isometric drawing. Costs are estimated using 1995 data for the upper midwest and listed is U.S. dollars.

Initial Acquisition Labor Savings

- Design, design review and material acquisition costs. Since this system represents an initial JRT installation at this location, the specifiers decided that the design, review and acquisition of the system would be no different with either design. After the installation, they report that the project went very "smoothly" and they can anticipate savings in design, review and acquisition of future JRT installations.

- Elimination of field fabrication of flanged custom length pipe. It takes about 1.15 hr to completely cut, thread, flange, flare and block the two ends of a 2" PVDF-lined spool. There are thirty-seven spools in the conventional flanged system design, representing a total fabrication time of 42.55 hours. It takes about 0.6 hours to cut, align, trim, butt-fusion weld and install a CONQUEST® connection. There are thirty-seven CONQUEST® connections in the system, with a total installation time of 22.2 hours.

- Cost of installation It takes about 0.4 hr to install the nuts, bolts and flange shield of a 2" diameter connection. There are forty-nine flanged connections in the conventional design, for a total installation labor of 9.80 hours. The CONQUEST® connections are installed during the fabrication process outlined above, so there is no additional installation time since there are no nuts, bolts or spray shields used.

- Start-up costs. It's assumed that the cost to hydrotest the system would be identical for conventional piping and for a JRT system. However, the costs for hydrotesting of the conventional system would be higher if leaks occurred at the flanged connections and had to be corrected during the hydrotest. A leak occurring in a CONQUEST® connection during hydrotest would not be likely. These costs could be included based on previous experience at the site. However, the cost of the 24-hr retorqing of the flanged connections is tangible, at 0.2 hr per connection. With forty-nine flanged connections, there's an additional 9.8 hrs needed to start up the conventional system. The conventional PLP system takes nearly fifty hours more to fabricate, install and start-up than the same system that fully incorporates JRT to eliminate flanged connections. At $50.00 per hour, the seemingly "less expensive" system is nearly $2500 more expensive to install and commission.

So, if both the initial acquisition costs and the initial acquisition labor is considered, the total installed cost of the system that incorporates CONQUEST® flangeless joints and MULTI-AXIS® precision-bent piping is $3,800 less than the same system installed with conventional flanged plastic-lined piping. This savings increases if the operating and maintenance costs are also considered.

Operating and maintenance costs

- Annual monitoring and record keeping. It costs about $75.00 annually to monitor and record the testing of each flanged connection in a conventional PLP system. With forty-nine flanged connections, the system will cost an additional $3,675 per year to maintain.

- Annual retorquing. The cost to retorque each connection is about $10.00 per year, creating an additional $490 in annual operating costs not required to maintain a JRT system. In certain critical services, retorquing is required semi-annually or quarterly.

- Other costs. Leaks and shut-downs can be very expensive, yet each location will have to evaluate their annual cost potential based upon system configuration, location, process conditions and history. These costs should not be overlooked, but are beyond the scope of this study.

Initial Acquisition Costs

- Pipe, fittings, flanges, locking collars and CONQUEST® connections. The conventional flanged system consists of: ten 90° elbows; two standard tees; thirty-three plain end pieces of pipe, 20 ft (6.1 m) long; one plain-end piece of pipe, 10 ft (3 m) long; seventy-four threaded flanges; and, seventy-four locking collars. The net price is $17,032. If the system is designed with JRT, then it consists of: two MULTI-AXIS® four-bend pieces, 20 ft (6.1 m) long, plain one end, flanged the other; one MULTI-AXIS® two-bend piece, 20 ft (6.1 m) long, plain both ends; two CONQUEST® tees; thirty-one plain-end pieces of pipe, 20 ft (6.1 m) long; and, thirty-seven CONQUEST® connectors. It has a net price of $20,073. Thus the system that utilized JRT has a piping material cost premium of $3,041 (the difference between $20,073 and $17,073). If the economic study ended at this point, then the conventional, flanged PLP system would be specified. However, complete life cycle cost analysis reveals that it is the most expensive of the two alternatives.

For the other initial costs (nuts, bolts, flange protectors, and registration of connections) consider the relative cost differences between the two systems.

- Nuts and bolts. A set of four bolts or studs and nuts cost about $3.00 to $5.00 for a 2", four bolt flanged connection. The specification of fluorocarbon-coated studs or bolts can increase the cost of the hardware to $10.00 to $12.00 for the connection.

In this example, uncoated bolts and nuts, with a cost of $4.00 per set, are used on the forty-nine flanged connections. Total nut and bolt cost is $196.

- Flange protectors or spray shields Simple polyethylene spray shields cost about $5.00 each, and shields of PVDF (the same material at the pipe liner) cost about $10.00 each. Sometimes, fluorocarbon drain guards are specified for especially critical areas to permit collection of any leaks or drips. These deluxe guards can cost up to $25.00 per connection. In this system, PVDF spray shields, at $10.00 each are used on each of the forty-nine flanged connection with a total shield cost of $490.

- Registration of connectors Each flanged connection is labeled with a bar code and its location and chemical service is recorded on a corporate database system at a unit cost of $75.00 per connection. The total cost for the forty-nine flanged connections is $3,675. Many connections are totally eliminated through the use of MULTI-AXIS in the JRT alternative and the remaining CONQUEST® connections are considered to be permanent connections and thus are not subject to periodic monitoring and record-keeping.

- Other possible savings. In this example, an existing pipe rack is used and the piping system isn't insulated or heat traced. However, in other installations where this isn't the case, these savings should be considered. For example the cost to insulate a 2" (50 mm) flange set is $75-90 if common calcium silicate insulation is used.

Life Cycle Cost Comparison - 2" diameter PVDF-lined PLPP Field

  Conventional Flanged PLP   Joint Reduction Technologies JRT vs. Flanged  
  Qty Unit
Price, $
Ext
Price, $
  Qty Unit
Price, $
Ext
Price, $
 
Initial Acquisition Costs  
Pipe, fittings, flanges, collars and connectors   17,031.60   20,072.55 3,040.95  
Nuts & bolts for connection 49 4.00 196.00   -196.00 credit
Flange protectors 49 10.00 490.00   -490.00 credit
Registration of connection 49 75.00 3,675.00   -3,675.00 credit


  Qty Unit House Ext Hours   Qty Unit Hours Ext Hours  
Initial Acquisition Labor, hours  
Field fabrication, 1.15 hr for flanged pipe spool 37 1.15 42.55  
Field fabrication, 0.6 hr for CONQUEST® connection   37 0.60 22.2  
Install nuts, bolts, shields 0.4 hr per connection 49 0.40 19.60  
24 hr retorque, 0.2 hr per connection 49 0.20 9.80  
Total Hours   71.95   22.20  
Extra Hours for Conventional PLP   45.75  


  Conventional Flanged PLP   Joint Reduction Technologies JRT vs. Flanged  
  Qty Unit
Price, $
Ext
Price, $
  Qty Unit
Price, $
Ext
Price, $
 
Initial Acquisition Labor
Extra hours @ $50/hr
49.75 50.00 2,487.50   -2,487.50 credit
Difference in Cost of Initial Acquisition Materials and Labor -3,807.55 credit
Annual Operating and Maintenance Costs
Monitor & record connection 49 75.00 3,675.00   -3,675.00 credit
Retorque connection 49 10.00 490.00   -490.00 credit
Annual Operating Cost Difference -4,165.00 credit

Discussion of results

A simplistic comparison of the cost of an un-installed CONQUEST® connector with the cost of two threaded flanges would have clearly supported the continued use a flanged plastic-lined pipe. That approach would have shown it "cost" about $60 per connection to have a flangeless joint. This approach ignores the total elimination of any type of connection due to the use of MULTI-AXIS piping and the total cost of the hardware and labor needed to install a piping system. It obviously doesn't consider the long-term maintenance cost of the connections, either.

A slightly more sophisticated approach would have been to consider the total cost of the pipe, fittings, flanges, collars and connectors for each system. But, this evaluation would also have resulted in an incorrect specification. This is because the piping materials for a conventional system are about $3,040 less expensive than for a JRT system with the same configuration.

It isn't until the installation hardware (nuts, bolts, spray shields) and labor is considered that the truly "less expensive" alternative is revealed. A JRT system costs about $3,800 less to purchase, install and commission than does the same system in conventional flanged PLP.

The recurring annual cost savings realized by elimination of monitoring, retorquing and record-keeping make the JRT system $4,165 less expensive to operate each year. This can create a cost savings of tens of thousands of dollars over the life of the system, more than paying for the initial investment.

Obviously, each piping system is different and operating conditions are sometimes difficult to predict. As this study shows, there's no quick answer to the question, "How much more will it cost me to use JRT?" The answer is "it depends" and it's usually less expensive to use JRT instead of conventional PLP when all costs associated with installation and maintenance are considered.

We've based our study on costs in the upper midwest and are interested in the experience in your facility. Please contact us to share your comments and insight.



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