A labor unit for purposes of this website, is expressed in terms of manhours to install a unit of material (such as a foot of pipe), an individual item (such as a fitting or valve), or perform a specific task (such as welding a joint). In developing the labor units set forth on this website, MCAA reviewed the many elements that make up installation labor. They are: Receiving Unloading Stockpiling Distribution Handling and erection Fitting and joining Pressure testing There are two basic approaches to laboring piping systems in the WebLEM. The traditional method is called the Component Method, and it is based on using labor units that represent all activities necessary for the installation of one component (such as a 90 elbow or a tee). For piping, the unit is in manhours per foot and for components such as fittings, the unit is represented by each. The Component Method Expressed Simply is: Base Labor + Handling and Erection + Joining + Hydrostatic Testing = Manhours Per Unit. The second method, developed and published by MCAA in 2013, is called the Work Activity Method. Labor units in the Work Activity Method are simply manhours per activity. In this method each activity has a different labor unit, so the labor to make a joint is separate from the labor to handle and erect the item as is the testing labor for the item. Because the basis for these two laboring methods is so different, estimators need to take extreme caution if they intend to use a combination of the two methods within the same estimate. The two methods are not designed to be combined, instead they are designed to give the contractor a choice at the system take-off level. Once an estimator has chosen one particular method, it s advisable that he (she) stick with that method for the entire estimate. Regardless of the method you choose, each and every item in your estimate requires manhours. In the development of this website, MCAA took extreme care to assure the proper relationships of the labor units to each other across the full scope of sizes and pressures for various materials and joining methods. Each labor unit has been derived from an empirical formula and proven over many years to be accurate and consistent.
The following conditions are assumed to exist: if conditions other than those listed below are encountered, correction factors must be applied to the units contained herein. SEE SECTION ON CORRECTION FACTORS FOR SOME OF THESE CONSIDERATIONS. All work is to be installed in 1 st, 2 nd or 3 rd floor, or 1 st or 2 nd Basement. Material stockpile is to be within two hundred (200) feet of work areas. Material is to be put in place at ten (10) feet or less above floor. (Except thirteen (13) feet for hanger rod and inserts, beam clamps, etc.) All work is to be performed off a reasonably hard and level surface. All work is done by experienced mechanics knowledgeable in the materials installed. Average working conditions and productivity exist. That material handling for inside work is as follows: 1. 0-250 lbs. Material handled by hand by two men; use of chain falls or similar tools. 2. 251-1,000 lbs. Material handled by use of a Roustabout; cannon carrier, chain falls, etc. to move and put material in place. 3. 1,001-10,000 lbs.- Material handled by small rig, lift jacks, rollers, etc. to move and install into place (personnel to operate equipment not included). Thread joints are to be made on a pipe machine. Material handling in wide-open spaces as follows: 1. Pipe distribution directly from delivery truck by stringing along route of pipe. 2. Material handling by power equipment. (Personnel to operate equipment not included). There has been no attempt to establish criteria for Union Jurisdiction on any of the items contained in this manual by placing them in a particular section of the manual. Labor is for productive hours only. Add for Non-Productive labor. Labor is based on field assembly (Any savings resulting from shop fabrication would have to be reflected when applying your labor productivity factors). For shop fabrication versus field installation breakdown, the WebLEM Committee recommends using a split of 16% for fabrication shop handling and 84% for field handling and installation. These numbers are based on data gathered and are intended to represent average conditions. Each contractor's actual split may be different based on their respective fabrication shop material flow and the specific job site conditions. Spool pieces are a fabricated item, purchased and delivered ready for installation. Special consideration shall be given to in-line items such as flow meters, control valves and expansion joints as it relates to testing and flushing procedures. In most cases the contractor cannot test or flush through these items and dummy spool pieces may need to be installed and then
removed. Labor related to the installation and removal of the dummy spool pieces is not included in the WebLEM as part of the labor units for the specialty item. All material and equipment on a project requires labor for installation. It is absolutely essential to read the footnotes at the bottom of each table! The following items pertain only to the Component Method of estimating: 1. Gaskets and bolts and the handling thereof are included in flange man-hours. 2. Labor hours for the installation of the coupling are included in the piping system. 3. Couplings have been labored in the fitting section to be used for joining non-standard lengths of pipe. For example; cutting 20 lengths of copper tubing to fit into an elevator would require an additional coupling during installation. 4. When fittings are installed back to back, a correction factor should be applied to compensate for the reduction in the number of fitting joints. 5. In threaded systems, if an item contains both female and male joints, only the female joint is considered in the calculation of the labor unit. Example: Black Malleable Iron 90 Elbow has two joints used in the calculation. A Street 90 Elbow however only has one joint used in the calculation. 6. Labor to install rubber gaskets such as used in cast iron service weight or XH fittings are included in the fitting and pipe labor units. The following items pertain only to the Work Activity Method of estimating. This method of estimating requires that every single activity to fabricate and install a spool be considered for a complete estimate of the labor hours: 1. Pipe, Fitting, Flange, Nipple and Valve Handling: These tables contain the labor for handling the item and for installation of that item and these tables are required. 2. Pipe Cut and Bevel. If the material is carbon steel, there is a table with the cut and bevel combined into one operation. Other alloys require both a cut and bevel from separate tables. 3. TIG Root: Use this table if a TIG root is required. 4. Inert Gas Purge: Use this table if an inert gas purge is required. 5. Preheat: Use this tables if preheat is required. 6. Joints: Use these tables to establish the labor hours for the buttweld, socket weld, thread, or groove joints. 7. Stress Relieving: Use these tables if stress relieving or post weld heat treat is required. 8. Bolt Up: These tables are used for ALL flanged joints. 9. In-Line Specialty Items: These tables contain handling and installation labor for all In- Line Specialty item. The joints associated with each specialty item are not included and must be accounted for separately. 10. Hydro-testing: The hydro-test tables are for flanged ends or plain/beveled ends to install and remove blanks during the hydro-testing process. Each table also contains additional labor hours per foot of pipe run to establish the hours required for filling, testing and draining the run of pipe. Make sure you add the additional hydro-testing hours as shown in these tables. 11. There are other activities to consider such as drilling holes, fillet welds, layout and flame cutting of plate and machining the inside of pipe of fittings (counter-boring). Use these tables if required.
Labor units for pipe, valves, fittings, etc do not include labor for the installation of hangers. See the hanger section for applicable labor units.
The Labor Units DO NOT include the items listed below regardless if used in the Component Method or Work Activity Method: 1. De-Watering 2. Chemical and Mechanical Pipe Cleaning 3. De-greasing 4. Performance or other special testing 5. Non-Destructive testing of welds or any other weld testing 6. Chill rings 7. Temporary operations (operation of equipment or systems for benefit of others such as temporary heat) 8. Boiler cleaning, boilout 9. Flushing and draining of systems 10. Refilling and venting of systems 11. Traps shipped with blanks, floats and/or thermostatic elements shipped separately 12. Labor for forming and/or pouring thrust blocks or installing tie rods 13. Instructions to operating personnel 14. Operational tests 15. Balancing and adjusting systems 16. Start up procedures 17. Valve charts and tags 18. Equipment and System identification 19. Shop drawings (such as sleeve and insert drawings) 20. As built drawings 21. Installation of floor & ceiling escutcheons 22. Caulking of sleeves 23. Reconditioning and cleaning of owner equipment and material 24. Cleanups 25. Special torque requirements 26. Non-productive supervision 27. Excavation and backfill 28. Shoring and tamping 29. Labor to perform X-ray quality welding The Labor Units DO NOT include the items listed below if used in the Component Method: 1. Preheating and/or stress relieving 2. Inert gas purge IT IS ABSOLUTELY ESSENTIAL THAT FULL CONSIDERATION BE GIVEN TO THE FOOTNOTES AND SPECIAL CONDITIONS LISTED ON THE VARIOUS PAGES OF THIS MANUAL.