JOINT FIT UP AND ALIGNMENT

NCCER UNIT 10

INTRO

• JOINT DESIGN AND SETUP AFFECT THE SAFETY AND QUALITY OF A COMPLETED WELDMENT.

• ALL OF THESE ARE COVERED BY CODES AND SPECIFICATIONS THAT MUST BE FOLLOWED.

• SPECIAL TOOLS FOR FIT UP AND ALIGNMENT WILL BE DISCUSSED IN THIS UNIT.

CODE CHANGES • CODES ARE REVIEWED AND UPDATED AS NEEDED. WHEN A CODE IS

UPDATED, THE CODE CAN BE REISSUED WITH AN UPDATED YEAR SUFFIX OR AS AN ALTERNATIVE, ADDENDUM SHEETS MAY BE ISSUED.

• CHANGES ARE TYPICALLY HIGHLIGHTED TO SHOW CHANGES.

• THE ASME UPDATES THE ENTIRE CODE EVERY _______ YEARS. AN ADDENDUM IS ISSUED ________.

• THE YEARLY ADDENDUM IS IDENTIFIED BY PLACING THE LETTER ___ IN FRONT OF THE YEAR ON THE COVER OF THE CODE.

WPS

• A _____ IS A WRITTEN SET OF INSTRUCTIONS FOR PRODUCING SOUND WELDS.

• ALL WELDING REQUIRES THAT ACCEPTABLE INDUSTRY STANDARDS BE FOLLOWED, BUT NOT ALL WELDS REQUIRE A WPS.

• THE REQUIREMENT FOR THE USE OF A WPS IS OFTEN LISTED ON THE _____________ AS A NOTE OR IN THE TAIL OF THE WELDING SYMBOL.

WPS

• EACH WPS IS WRITTEN BY AN INDIVIDUAL WHO KNOWS WELDING CODES, SPECS, AND INDUSTRY PRACTICES.

• IT THEN BECOMES THE RESPONSIBILITY OF THE CONTRACTOR TO TEST AND QUALIFY THE WPS BEFORE USING IT.

• THE RESULTS OF TESTING ARE RECORDED ON A _______. THE WPS AND PQR MUST BE KEPT __________.

FIT UP GAUGES AND MEASURING DEVICES

• BEFORE MAKING A WELD, THE JOINT MUST BE FIT UP AND CHECKED TO ENSURE IT CONFORMS TO THE WPS OR SITE QUALITY STANDARDS.

• THE MOST COMMON TOOLS USED TO LAY OUT AND CHECK JOINT FIT UPS ARE STRAIGHTEDGES, SQUARES, LEVELS, AND HI-LO GAUGES.

STRAIGHTEDGES

• STRAIGHTEDGES ARE USED TO SCRIBE STRAIGHT LINES AND CHECK JOINT ALIGNMENT.

• ALWAYS CHECK A STRAIGHTEDGE FOR ________________, HEAT CAN CAUSE DISTORTION AND IF THIS HAPPENS THE STRAIGHTEDGE IS NO LONGER GOOD.

SQUARES

• TWO TYPES ARE TYPICALLY USED…..

• PIPEFITTERS SQUARES- USED TO MEASURE ANGLES AND CHECK SQUARENESS.

• COMBINATION SQUARES- TYPICALLY SMALLER, HAVE ATTACHMENTS THAT SLIDE AND LOCK ALONG A GROOVE ON THE BLADE.

• THE ________________ IS USED TO MEASURE ROUND STOCK AND TO LOCATE THE CENTER OF SHAFTS OR OTHER ROUND OBJECTS.

LEVELS

• LEVELS ARE USED TO CHECK THAT LAYOUTS ARE LEVEL (HORIZONTAL) AND PLUMB (VERTICAL).

• LEVELS USE A __________ IN A GLASS VIAL TO CHECK LEVEL AND PLUMB.

• THE BUBBLE MUST BE CENTERED IN THE VIAL TO ENSURE THE LEVEL IS CORRECT.

• TORPEDO LEVELS HAVE THREE VIALS: ONE TO CHECK LEVEL, ONE TO CHECK PLUMB, AND ONE TO CHECK 45 DEGREE ALIGHNMENT.

HI LO GAUGES

• THE MAIN PURPOSE OF A HI LO GAUGE IS TO CHECK FOR ______________________, ALTHOUGH PLATE JOINT MISALIGNMENT CAN ALSO BE CHECKED.

• THE NAME COMES FROM THE RELATIONSHIP BETWEEN THE ALIGNMENT OF ONE PIPE TO THE OTHER PIPE, WHICH IS CALLED HIGH-LOW.

FIT UP TOOLS

• MANY TOOLS HAVE BEEN DEVELOPED TO AID PLATE AND PIPE FIT UP. SOME ARE SPECIALTY TOOLS AND OTHERS ARE COMMON HAND TOOLS.

• THE FOLLOWING ARE COMMON FIT UP TOOLS….

HYDRAULIC JACKS

• WHEN USING A HYDRAULIC JACK, NEVER WELD DIRECTLY ON THE JACK BASE OR RAM.

• ALWAYS PROTECT THE RAM FROM WELD SPLATTER.

• IF THE RAM IS OFF THE GROUND, SECURE IT WITH ROPE OR CHAIN.

CHAIN HOISTS (CHAIN FALLS)

• CHAIN HOISTS, ALSO CALLED FALLS, ARE USED TO LIFT OR LOWER WELDMENT PARTS.

• ALWAYS SECURE THE CHAIN HOISTS OVER THE WELDMENT WITH AN _______________ WRAPPED AROUND A SECURE STRUCTURE.

• NEVER HANG CHAIN HOISTS FROM PIPING, DUCTS, CONDUIT, OR RACEWAYS.

COME-ALONGS

• COME-ALONGS CAN BE USED FOR VERTICAL LIFTING AND PULLING AT ANGLES.

PLATE ALIGNMENT TOOLS

• SPECIAL TOOLS ARE MANUFACTURED FOR ALIGNING PLATE.

• TYPICAL CONFIGURATION OF AN ALIGNMENT TOOL CONSISTS OF A YOKE, ADJUSTMENT ROD, GAP PLATE, AND ROOT BAR.

• THE ____________ CAN BE CHANGED TO MATCH THE SPECIFIED ROOT OPENING.

PIPE FIT UP TOOLS

• PIPE JACKS AND ROLLERS ARE USED TO SUPPORT PIPE FOR FIT UP AND WELDING.

• JACK STANDS AND ROLLERS ARE NECESSARY TOOLS IN THE PIPELINE WELDING INDUSTRY.

CHAIN CLAMPS

• _________________ ARE USED TO ALIGN AND HOLD PIPE FOR FIT UP AND TACKING.

• THE CHAIN IS PASSED AROUND THE PIPE AND SECURED, THE SLACK IN THE CHAIN IS THEN REMOVED USING A JACK SCREW TO PULL THE PIPE TIGHTLY AGAINST THE CLAMP.

• THESE CLAMPS ARE IDEAL FOR JOBS IN WHICH 100 PERCENT ________ AND _________ IS REQUIRED BEFORE THE CLAMP CAN BE RELEASED.

WELD DISTORTION

• DISTORTION IS THE EXPANSION AND CONTRACTION OF METAL AS IT RESPONDS TO CHANGES IN TEMPERATURE.

• DISTORTION CANT BE PREVENTED AS LONG AS THE METAL EXPERIENCES CHANGES IN TEMPS CREATED IN THE WELDING PROCESS.

DISTORTION

• THE DEGREE OF DISTORTION IS DIRECTLY RELATED TO THE ____________ GENERATED DURING WELDING.

• TWO OF THE BIGGEST FACTORS IN DISTORTION ARE COEFFICIENT OF THERMAL EXPANSION AND THE SPECIFIC HEAT PER UNIT VOLUME.

• METALS WITH HIGHER VALUES FOR THESE TWO FACTORS WILL EXPERIENCE A HIGHER DEGREE OF DISTORTION THAN THOSE WITH LOWER VALUES.

CONTROLLING DISTORTION

• DISTORTION CAN BE CONTROLLED USING VARIOUS TOOLS AND TECHNIQUES.

• IT CAN ALSO BE CONTROLLED BY USING CLAMPS AND BRACES, TACK WELDS, AND CONTROLLING THE AMOUNT OF WELD MATERIAL.

• EXCESS FACE REINFORCEMENT ACTUALLY REDUCES THE STRENGTH OF A WELD AND IS THEREFORE _______________ BY WELDING CODES.

JOINT FIT UP

• PROPER FIT UP AND EDGE PREPARATION ALSO REDUCE THE AMOUNT OF WELD REQUIRED.

• OPEN ROOT JOINTS SHOULD HAVE A ROOT OPENING FROM _____ TO ______ WIDE.

WELDING SEQUENCE

• A WELDING SEQUENCE INVOLVES PLACING WELDS AT DIFFERENT POINTS ON A WELDMENT SO THAT SHRINKAGE IN ONE AREA IS COUNTERACTED BY SHRINKAGE IN ANOTHER AREA.

• WELDING SEQUENCES ARE OFTEN PERFORMED BY TWO INDIVIDUALS WELDING ON ___________ SIDES OF A JOINT AT THE SAME TIME.

• THIS IS KNOWN AS ___________ WELDING, WHICH IS ONE OF THE BEST WAYS AT CONTROLLING DISTORTION.