Monday, August 07, 2017

Stainless Steel Waterstop for High Heat Applications

Earth Shield® Stainless Steel Waterstop can stop even the most corrosive fluids in their tracks, even at severely elevated temperatures. A variety of metals, grades, and gauges are available. Earth Shield® utilizes 20 gauge 316 low carbon as our standard alloy, which offers broad spectrum corrosion resistance to most aggressive media, and is virtually untouched by the deleterious effects of ozone, making it an ideal choice for ozone contactor structures used in modern water treatment plants.

Hydrophobic SS Waterstop
1. Prevents the passage of extremely corrosive fluids (even at elevated temperatures) through concrete joints by creating an internal dam, spanning both sides of and running continuously along the concrete joint.
2. The most difficult to install waterstop, as split-forming is always necessary (with the exception of retrofit profiles). Also, TIG or MIG welding is required.
3. Contains no plasticizer to leach out (unlike PVC) from exposure to hydrocarbons, acids, ozone, ultraviolet radiation, or time.
4. Products are available for above- or below-grade; limited-moving or non-moving applications.
5. Designed to last the life of the concrete structure.
6. Able to withstand extreme temperature conditions (high heat, LNG, etc).

Earth Shield® Stainless Steel Waterstop is available in many standard shapes and sizes, including profiles for new construction and retrofit. All change of direction fabrications can be pre-manufactured leaving only straight butt welding for the field.

Friday, June 02, 2017

Waterstop Physical Properties

waterstop, waterstops, chemstop, fuelstop
There are a number of physical properties you should consider when choosing the right material for your waterstop application. These include hardness, tensile strength, modulus, elongation, tear resistance, and compression set.
Hardness — ASTM D2240
Hardness is resistance to indentation under specific conditions. There are currently two hardness tests that predominate in the rubber and plastic industry: Shore durometer and International Rubber Hardness Degrees (IRHD). Most commercially available waterstops use the Shore A scale; therefore, to evaluate waterstops look at the listed value and understand that the higher number means the harder (and stiffer to flexure) waterstop product.
100% 
Tensile Strength — ASTM D412
Typically noted in either pounds per square inch (psi) or megapascals (MPa), tensile strength is the amount of force required to break a plastic or rubber waterstop specimen. (To convert from MPa to psi, simply multiply the MPa figure by 145. For example, 14 MPa converts to 2,030 psi. Converting from psi to MPa is just a matter of dividing the psi number by 145.
Modulus — ASTM D412
Modulus is the force (stress) in pounds per square inch (psi) required to produce a certain elongation (strain). 100% is the most widely used figure for testing and comparison purposes of commercially available waterstops. Generally speaking, the harder a waterstop (ASTM D2240), the higher its modulus. Because it is basically a measure of tensile strength at a particular elongation (rather than at rupture), modulus is also known as tensile modulus or tensile stress.


Ultimate Elongation — ASTM D412
Elongation is the percentage increase in original length (strain) of a rubber or plastic waterstop specimen as a result of tensile force (stress) being applied to the specimen. Elongation is inversely proportional to hardness, tensile strength, and modulus. Therefore, the greater a waterstop’s hardness, tensile strength, and modulus, the less it will elongate under stress. It takes more force to stretch a hard waterstop having high tensile strength and high modulus than to stretch a soft material with low tensile strength and low modulus. Ultimate elongation is the elongation at the moment the specimen breaks. Per ASTM D412, ultimate elongation is expressed as a percentile; therefore, when comparing waterstops the higher the number (%) the better.

Tear Resistance (aka Tear Strength) — ASTM D412
Tear resistance (also known as tear strength) is resistance to the growth of a cut or nick in a waterstop specimen when tension is applied. Values are usually expressed in pound force per inch (lbf/in), so again, the waterstop with the higher value is superior, as it is more resistant to tearing.

Compression Set — ASTM D395
Compression set is the permanent deformation remaining when a force applied to a waterstop specimen for a period of time is removed. Tested under ASTM D395, compression set is expressed as a percentile that relates to the percentage of deformation compared to the waterstop’s original thickness. Therefore, a low value is better as it denotes the waterstop did not “take a set” and returned close to its original shape and size after the force is removed. A high value means the waterstop became deformed (squished) under pressure and did not return to its original shape and size. Compression set represents the percent of deflection that did not return.
There are a number of physical properties you should consider when choosing the right material for your waterstop application. These include hardness, tensile strength, modulus, elongation, tear resistance, and compression set.
Drinking Water Safe — NSF 61
Water is arguably the most valuable resource in the world. Today’s water treatment, distribution, and storage projects are under ever-increasing layers of regulations and requirements, one of the foremost being that components and materials that contact potable water not have potential adverse human effects.


NSF Standard 61 was developed to establish minimum requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, components, and materials used in drinking water systems.
Standard 61 is intended to cover specific materials or products that come into contact with drinking water, drinking water treatment chemicals, or both. The focus of Standard 61 is evaluation of contaminants or impurities imparted indirectly to drinking water.
In the U.S., 47 of 50 states have legislation that requires compliance with NSF Standard 61. Products that are NSF Certified against NSF/ANSI Standard 61 demonstrate compliance with both Canadian and U.S. Plumbing Codes. NSF Certification and Testing is widely accepted. NSF data is recognized by ASSE, BOCA, IAPMO, ICBO-ES, SBCCI, City of Los Angeles and many others.
Very few waterstops have NSF 61 certification, which is pretty surprising considering that waterstops are often installed in drinking water facilities. I believe this is one of the more important requirements for a waterstop (NSF 61 certification) and that specifiers should require it.

Resistance to Chemicals — ASTM D471
ASTM D471 tests the waterstop in a given concentration of a specific fluid* for 166 at hours at a specified temperature* (*customer request of fluid and usually 23°C for the temperature). After the testing time has elapsed, the waterstop is removed from the fluids and a variety of physical tests are performed that gauge its durability and corrosion resistance to the material it was immersed in. A waterstop that performs well in this test can be considered “chemical resistant,” but only to the specific fluid tested. In other words, a waterstop could be a good choice for fuel oil, but a poor choice for hydrochloric acid. This distinction is important, as no one metal or polymer waterstop is chemically resistant to everything.


Resistance to Ozone — ASTM D1171
ASTM D1171 tests the waterstop in a given concentration* of ozone (*usually expressed in Parts Per Million (PPM) or Parts Per  Hundred Million (PPHM). After the testing time has elapsed, the waterstop is removed from the ozone chamber and a variety of physical tests are performed that gauge its durability and corrosion resistance to the ozone it was exposed to. Because many waterstops fail in high concentrations of ozone, this is an important test when selecting a waterstop for an ozone contactor application. A waterstop that performs well in this test can be considered “ozone resistant,” but only to the concentration tested to.


Tuesday, May 09, 2017

How to Weld Plastic Waterstop

An initial warm up time of approximately 15 minutes is required to heat up splicing iron to the required temperature. Preheat Iron up to the following:
• For TPV / TPER Waterstop: 410 to 430°F
• For PVC Waterstop: 350 to 380°F
It is recommended to verify temperature using an external thermometer.
NOTE: The Peel and Stick Teflon® Cover is to remain on the iron during the welding process. DO NOT REMOVE.
CAUTION: Too high of a temperature will result in damage to waterstop welds, splicing iron cover, and possibly splicing iron.
1. Always cut square ends before welding waterstops. Never weld to extruded ends. Use flat work table to create field splices. Work area should be solid and have access to power supply and have jigs and fixtures to aid splicing.
2. Cut ends square, using a razor knife or circular saw equipped with a carbide tipped blade (10” diameters with 40 teeth) to ensure matching edges.
3. Preheat the iron to the desired temperature ranges. Place iron between butt ends. Keep waterstops in place until approximately 3/16” bead forms on each side of waterstops. Quickly remove splicing iron and gently press waterstops ends together until they bond (approximately 3 to 5 minutes or cool to touch). Cold water may be sprayed on waterstops to expedite the bond.

Monday, May 01, 2017

Save Time and Money with Shop Made Fittings

Why the Engineer Should Specify Shop Made Fittings

Shop Made Fittings are recognized and specified worldwide by major engineering firms. The U.S. Army Corps of Engineers also specified Shop Made Fittings in the July, 1995 revision of CEGS Section 03250. Shop Made Fittings are specified because they work. Edge welding waterstop seriously compromises the integrity of any project. Even the limited movement of concrete during the coefficient of expansion and contraction can be too much for edge welded waterstop. The edge welded waterstop lacks the proper tensile strength and does not maintain the characteristics of the parent material (bulb or rib continuity). Consequently, the waterstop often tears at the most critical junction: the change of direction. Since all waterstops are designed to act as a continuous, fluid-tight diaphragm which fluids (generally water) traverse, the structure that uses edge welded waterstop will naturally leak, as fluids migrate to any tears in the weld and pass through to the other side of the joint.

Structures that use Shop Made Fittings will significantly reduce these waterstop failures. The tensile strength of the weld will be at least 80% of the parent material. Continuity of the bulbs and ribs shall be maintained across the weld. In other words, the waterstop will perform as intended and last the life of the structure.

CAD Drawings

J P Specialties has a large library of CAD drawings that illustrate the many uses of various Shop Made Fittings and explain waterstop's role in creating a fluid-tight structure.

Why the Contractor Should Use Shop Made Fittings

JP Specialties certified welding crew can efficiently manufacture large quantities of top-quality Shop Made Fittings with speed on our exclusive XLT-2000 Waterstop Splicing Tables. Therefore, we are able to pass the savings on to the end user: the contractor. Besides saving money, the contractor who uses Shop Made Fittings will save time. A standard flat cross has twelve cuts and seven welds. By using Shop Made Fittings, all of the cuts and three of the welds will be eliminated. The number of welds can be further reduced by using modules.

What are Shop Made Fitting Modules?

Modules are custom Shop Made Fittings that are delivered to the jobsite as a complete unit, rather than a collection of parts. For example: a box culvert with a longitudinal joint would typically require four vertical ells and two flat crosses. Even with Shop Made Fittings this would be sixteen butt welds (straight edge to straight edge) for the contractor in the field. With proper dimensions from building plans, J P Specialties will manufacture entire box culvert modules. In the box culvert example conveyed above, using modules, only four butt welds remain to be done in the field.

Modules work best when they are specified by the engineer during the design phase of the project, but they can also be used effectively during the construction phase with close collaboration between JP Specialties and the contractor. J P Specialties can clearly interpret project plans during any phase of construction and render how Shop Made Fittings or modules will improve the quality of your structure and save you money.

How Much Do Shop Made Fittings Cost?

Shop Made Fittings can be supplied at a cost savings to the contractor on most jobs, when compared to the time and labor necessary to fabricate the Waterstop in the field. Providing Shop Made Fittings will not only be more cost effective, but will ensure a timely installation, thus saving costly delays. In addition, our Shop Made Fittings will enhance your ability to meet stringent hydraulic tests required by engineers.

Saturday, April 22, 2017

Utilizing Two Waterstops in Concrete Joints

With waterstop, two is often better than one. If your concrete joint has the appropriate clearance, why not use one waterstop as your primary barrier and another as a secondary barrier as a kind of insurance policy? If the first system fails in any way due to manufacture or installation, the second system is there to ensure fluid-tight integrity at the concrete joint.

Because waterstop systems are relatively low cost, having a secondary product installed can be a wise and inexpensive investment.

Let me be clear, if a hydrophobic waterstop is properly installed, there really is no need for a secondary waterstop system. Regardless of polymer or manufacturer, these waterstop products really only leak from poor installation procedures and a lack of quality assurance. In my over 20 years in this industry, I am yet to see a waterstop burst or fail due to high hydrostatic water pressure. However, I often see improperly installed product that will result in failure and leakage.

A typical “belt and suspenders” approach would be to have an embedded hydrophobic on the high-pressure side of the joint and a hydrophilic or mastic strip-applied waterstop several inches away from it on the low pressure side. An alternative secondary waterstop would be an injection tube system placed on the low pressure side.

Another great option would be to utilize JPEB375 Integrated Capseal as the “belt” and JP211 Base Seal as the suspenders.

The benefits of redundancy in installed waterstop systems is great and the cost is low, especially when amortized over the extended life of the concrete structure they are installed in.

Thursday, April 20, 2017

Join New Concrete to Existing Concrete With Earth Shield Retrofit Waterstop

Earth Shield Part No. JP325T installed in an expansion joint.
Retrofit waterstop is designed to provide a fluid-tight seal between existing and new concrete construction, without resorting to the labor-intensive and structurally destructive saw-cut-and-grout method. It is ideal for constructing a new containment curb or wall to an existing slab, or joining a new slab to an existing wall. Special profile fabrications are available for columns and pipe penetrations.

All of our retrofit waterstops are sold as a system, and include all the necessary stainless steel bars and bolts. We also offer a high-quality chemical resistant novolac epoxy — VEN 1000. Earth Shield® retrofit waterstops are manufactured with our proprietary thermoplastic vulcanizate compound, which provides for unsurpassed chemical resistance.

Like all our thermoplastic vulcanizate waterstops, Earth Shield® retrofit can be heat-welded using a standard waterstop splicing iron. This allows for easy field fabrications, and allows the waterstop to function as a continuous, homogeneous, fluid-tight diaphragm. Waterstop change of directions can be purchased along with straight roll stock, and custom, fit-to-print waterstop modules are produced to order. Prefabricated ells, tees, tank pads, column fittings, and many others are in stock and ready to ship.

Tuesday, April 04, 2017

The Importance of NSF 61 Certification for Waterstop

NSF/ANSI Standard 61 was developed to establish minimum requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, components, and materials used in drinking water systems. Standard 61 is intended to cover specific materials or products that come into contact with drinking water, drinking water treatment chemicals, or both. The focus of Standard 61 is evaluation of contaminants or impurities imparted indirectly to drinking water. In the U.S., 47 of 50 states have legislation that requires compliance with NSF/ANSI Standard 61. Products that are NSF Certified against NSF/ANSI Standard 61 demonstrate compliance with both Canadian and U.S. Plumbing Codes. NSF Certification and Testing is widely accepted. NSF data is recognized by ASSE, BOCA, IAPMO, ICBO-ES, SBCCI, City of Los Angeles and many others. Earth Shield® Thermoplastic Vulcanizate Waterstop by J P Specialties, Inc. was the first commercial waterstop to achieve NSF 61 certification, and maintains this certification annually. Therefore, for your drinking water applications there is no more suitable product than Earth Shield® TPV Waterstop. Most commercially available waterstops do not have NSF 61 certification, so the designer should be wary in specifying these non-certified products.