It is important that the valve is designed as a dead end so that when it is closed 1 the joints of the nonpressurized side of the valve are not compressed and, as a result, overinserted and that 2 the joints within the required restraint length on the pressurized side do not pull apart. Tyton joint, field lok 350 and flange tyte gaskets meet the specifications, performance requirements and pressure ratings in accordance with standard. The most elementary 3d space truss structure is the tetrahedron. Prestressed concrete cylinder pipe pccp joints piping guide. This convenient new system provides both municipal and private consultants a reliable means of securing the necessary restrained joints in a water or wastewater pressure pipeline. Tee fittings require the restraint of all joints within a calculated length along the branch pipe. The restrained length along the branch of the tee connection, lb, provides frictional resistance that involves the entire circumference of the branch piping. The restraints have internal serrations that lock onto the pipe and give 360 degrees of contact and pipe wall support.
Report references print current page print report help. Tyton joint ductile iron pipe tr flex restrained joint pipe hp lok restrained joint pipe and fittings trxtreme restrained joint pipe hdss high. Conservative assumptions, along with an explicit safety factor, have been employed to assure a conservative design with an adequate overall safety factor. The problem with steel or timber beams is that, generally, they are deep but slim. As an example, for a 12inch ductile iron pipe, 3 feet of cover in a type 1 trench with a design pressure of 250 psi and static pressure of 70 psi, in medium silt soil, a 12inch, 45degree bend would need to be restrained for a minimum of 56 feet to avoid pipe joint separation.
There are two methods generally used to resist the unbalanced. Plug in values such as pipe material is being used, soil types, trench types, depth of bury, test pressures and the restraint length calculator will calculate the restraint length values. The difference is that thermal expansion between flanges remains inside the expansion joints. No need to download or install software, works in contemporary internet browsers. Soil conditions soils that offer more resistance will result in less restrained joints being required to contain an equal force in a less resistant soil type of pipe and its diameter pvc pipe will require more footage of restraint due to the nature of its outside slickness or grip. Ductile iron pipes, fittings, accessories and their joints. Pvc is known to exhibit viscoelastic behavior as it approaches its glassy transition tempe rature. Joint restraint products the series 1100 provides joint restraint for pvc pipetopipe joints, and it may be installed on new or existing systems. Types of restrained joint systems have evolved from concrete. By using this little web application you can solve any flat truss with a maximum of 30 nodes. Such forces, if not properly restrained, could cause the pipeline to move and disengage at the joints. Prestressed concrete cylinder pipe pccp joints piping. Its easytoassemble restrained joints would also prove useful because the crew had limited space in which to assemble the pipe when working near the creek.
Read on to learn why certalok is the smart choice for pvc restrained joint applications. Therefore, the area behind the thrust block must engage enough soil area to resist the resultant thrust. Restrained a joint pvc pressure pipe certalok vip restrained joint pvc municipal water pipe certalok vip restrained joint pvc pipe is the first nonmetallic restrained joint system designed for use in municipal water and fire protection systems. The restrained length of pipe lr, along the run of the tee and on each side of the tee, encounters passive bearing resistance from the soil that acts perpendicularly to the tee.
This is used to produce pipe sockets by heating and forming them over a mandrel. The bearing strength of the soil is expressed in pounds per square foot. Simple space trusses can be obtained by adding 3 elements at a time to 3 existing joints and joining all the new members at a point. Testable joints should not be considered a replacement for postconstruction hydrostatic pressure tests since they do not confirm the overall system integrity restrained joints or concrete thrust blocks and water tightness of connecting appurtenances such as valves and access manholes. The restraint design also requires the selection of a length of. It includes guidelines for the design of thrust blocking using the standard details and special design requirements for nonstandard thrust blocks and restrained. The restraints have internal serrations that lock onto the pipe and give 360 degrees of. Faqs and technical briefs unibell pvc pipe association. Download it now and be ready for your next installation. When restrained joints are used the pipeline becomes its own thrust block. What is the difference between restrained and unrestrained. These joints include ball and socket for subaqueous crossings, plainend coupled, threaded and coupled, and other variations of restrained joints. Check that the assumptions listed below meet or exceed your application.
The snap ring joint incorporates a split ring which is preassembled in the manufacturing plant so that it is recessed into a groove in the bell ring. Length of restrained pipe calculation water treatment. This free online truss calculator is a truss design tool that generates the axial forces, reactions of completely customisable 2d truss structures or rafters. Whenever there is a change in flow in a pressure pipeline. No free movement joints should allow relative vertical displacement of the panels. Four joining options for trenchless installation of pvc pipe. How many restrained joints do i need when designing a project. Now the need for costly concrete thrust blocks and corrodible steel tie rods is eliminated.
Thrust restraint design tyton lok calculator viadux. It has a wide range of applications including being used as a wood truss calculator, roof truss calculator, roof. The number of restraints or the distance to restrain is a function of numerous factors. Where and how to restrain joints in ductile iron pipe. Joints can easily be assembled with current tools and methods used for many years in the assembly of standard fastite joints. Engineer that can be used for a number of different design situations, including a thrust restraint calculator. Ebaa iron is an american family owned corporation with foundry and finishing facilities in eastland texas, albany texas, and cordele georgia. Lateral expansion joint is used in similar way as two single hinged or gimbal expansion joints. Calculation history it contains the list of all calculated fitting items for the current project. What is the difference between restrained and unrestrained beams. Rated up to 350 psi and fully warranted by specification rubber. Get the restrained joint pipe length calculator from the manufacturers to calculate how far the restrained joints need to be for a safe installation, in most cases you will need to restrain more than one length of pipe. With minimal input required, instantly compute the required length of restrained joint pipe for each and every bend, dead end, inline valve, tee and reducer that is plausibly available for the selected pipe diameter. This program is based on the equations and procedures found in the dipra brochure thrust restraint design for ductile iron pipe.
When joint restraint is required underground or aboveground, several types of restrained joints are available from american. In structural engineering, the term restraint is used to denote how much a beam is stopped from buckling sideways. American joints restrained coupling gland joint table no. Restrained joints are provided in all sizes 4 through 64 as shown below and described in this section.
The certalok restrained joint pvc pipe system is uniquely designed to offer significant cost, performance, safety and environmental advantages over bulldog joint options and materials. Romac thrust block restraintcalculatorhelp pipe fluid. Apr 23, 2006 the restraint length calculator, from ebaa iron, is to help with calculations for the design of restrained piping systems. Thrust restraint calculator ductile iron pipe research association. Tytonlok is not suitable for use on epoxy or fusion coated pipes and spigots or tytonxtreme pipe. A more detailed description of the joints used with ductileiron pipe is found in chapter 5 of this manual. Rslcos 2 l restrained length dependant upon pipe size type of fitting internal pressure depth of cover soil characteristics. Freemovement joints which are going to be heavily trafficked should be of an armoured type to minimise damage to the joint.
Below you can find the different joints that mcwane ductile offers for ductile iron pipe. Total length of restraint restrained joints restrained joints total length of restraint standard joint standard joint restraint of elbows scale. It also draws the deformed structure because of the loads applied to the joints. Forces on anchors are reduced because the pressure thrust is restrained by tied bars and hinged assemblies. Thrust restraint for pvc pipe can be easily and efficiently accomplished with mechanicaljoint. Fortunately napco had recently begun manufacturing the timetested certalok pipe in an 18in. American restrained joint pipe the principal standards relating to applicable features of american restrained joint pipe and fittings are ansiawwa c151a21. Us pipes mj field lok gasket provides the joint restraint that typically. Thrust forces restraint length calculator unibell pvc pipe. For more information on sizing and other specifications, download the submittal sheet located underneath each individual joint. Free movement joints allow for the horizontal movement of the slab caused by shrinkage and thermal effects. Download file here comments, questions, and answers about this modeling approach. Length of restrained pipe calculation hydrae mechanical 28 may 05 17. In order to counter the unbalanced forces that are created at these locations, the pipe and fittings must be mechanically restrained from.
Here are the features you will see with ebaa irons restraint length calculator rlc v7. Generalizing the structure of planar trusses to 3d results in space trusses. Star pipe products ductile iron pipe fittings, joint. Sigma rolls out new restrained joint calculator sigma. Tables below list number of adjacent pipe joints to be restrained for basic fitting configurations. January 1, 2002 w44 city utilities design standards manual revised. It has a wide range of applications including being used as a wood truss calculator, roof truss calculator, roof rafter calculator, scissor truss calculator or roof framing. When the calculator obtains the restrained length, it will inform the user which side of the line needs to be restrained with the help of a graphic. Faqs and technical briefs resources other resources faqs and technical briefs.
A floor slab is restrained by the ground on which it is built, by friction and by the keying effect of various foundations. The members are connected with balland socket joints. A thrust block prevents separation of joints and pipe movement by transferring the resultant thrust force at a bend to the undisturbed soil behind the thrust block. Supplemental restraint of deflected or beveled pipe joints is almost never required. Safety orange compound allows visual confirmation that a restrained joint gasket is installed. Ebaa iron restraints are 100% cast and manufactured in the united states of america. How to model an inline pressure balance expansion joint in autopipe. Mcwane ductile is now taking pipe protection to new heights with the innovative vbio, an.
Thrust restraint brochure a brochure outlining design theory and a design aid of restrained joint systems for ductile iron pipe. See detailed approach in the attached files for modeling an inline pressure balance expansion joint in autopipe. The system calulates the axial forces, the displacements of the joints, and the deformation of the elements of the structure. The restraint length calculator, from ebaa iron, is to help with calculations for the design of restrained piping systems. Joint restraints totally eliminate the need for thrust blocks. These joints can be used to resist axial tensile forces on the pipe due to unbalanced thrusts caused by internal pressure at fittings such as elbows, tees, and bulkheads. Get the restrained joint pipe length calculator from the manufacturers to calculate how far the restrained joints need to be for a safe installation, in most cases you will. A combination of tytonlok joints and thrust blocks where both contribute to the overall restraint of the system, is not recommended. Ductileiron pipe and fittings american water works. The calculated restraint length value obtained by the calculator is the length in feet. Restrained joints are also necessary for trenchless installation.
A calculator for thrust restraint design for ductile iron pipe. Tytonlok joints are not suitable for use with pn20 pipe. These were calculated using the joint restraint calculator available at. Romac thrust block restraintcalculatorhelp free download as. Automatically calculates results for both bare pipe and polywrapped scenarios. Restrained joints water and wastewater pipelines, under internal pressure, will experience unbalanced forces in the system as fluid flow is altered by change in direction.
790 1378 1559 1218 399 1184 493 1230 1342 574 472 317 1423 48 692 1116 361 1011 128 511 309 1053 711 186 729 256 244 403 754 611