Testing Materials for Strength and Parameters
When working with materials for trenchless repair and constructions, each piece must meet a set of standards as tested by ASTM International. Additionally, safe work condition set forth by OSHA is required.
Testing standards for materials is an essential aspect of manufacturing. For trenchless technology, however, this testing does not just include the strength and parameters of the equipment being used. It also provides project guidelines and operation requirements for specific items.
All standards are tested, and safety protocol comes from The American Society of Testing and Materials (ASTM International) and the Occupational Safety and Health Administration (OSHA) respectively.
In 1898, a group of engineers and scientists founded the American Section of the International Association for Testing Materials. Originally formed to address falling standards for steel used on railway lines, the group evolved to test other components used in technical settings. In 1902, the group renamed itself as the American Society of Testing and Materials or ASTM International.
To date, there are over 12,000 standards operating across the globe. ASTM International is headquartered in West Conshohocken Pennsylvania and operates in 140 countries. They have offices in Belgium, China, Canada, Peru, and Washington D.C.
ASTM International sets the standards for most industries including:
- Oil and Gas
This above list is a limited list. For a full list, see their website.
Trenchless Technology and Material Standards
Most of the products used in trenchless technology projects are regulated by ASTM International standard's testing.
Cured-in-place pipe, or CIPP, is a standard rehabilitation technique used in trenchless procedures. A resin permeated liner is pulled or pushed into place inside the existing line, or host pipe. To ensure proper installation, ASTM International has a series of standards, which include:
F1216 the Rehab of Existing Pipelines and Conduits by Inversion and Curing of Resin-Impregnated Tube
F1743: Rehab of Existing Pipelines and Conduits by Pulled-in-Place Installation of CIPP
D5813 Cured-in-Place Thermosetting Resin Sewer Pipe
According to the standards testing set forth by ASTM, all CIPP material must “consist of one or more layers of flexible needled felt or an equivalent nonwoven or woven material. It must be capable of carrying resin and withstanding installation pressure and curing.” All tubing must pass testing set forth by ASTM practices D790 and D683, for Flexural Strength and Modulus a tensile strength respectively.
Under ASTM, D790 polyester systems must have a flexural strength of 4,500 psi with a flexural modulus (initially) of 250,000 psi. The flexural modulus at 50-years should be 125,000 psi.
For filled polyester systems, the flexural strength is also 4,500psi with an initial flexural modulus of 400,000 psi and a flexural modulus at 50-years of 200,000 psi.
Vinyl ester systems need to have a flexural strength of 5,000 psi with an initial flexural modulus of 300,000 psi and a modulus at 50 years of 150,000 psi.
According to D638, all polyester CIPP systems must have a tensile strength of 3,000 psi. Filled polyester system tensile strength must also be 3,000psi while vinyl ester systems’ tensile strength must register 4,000 psi.
Horizontal Directional Drilling
Unlike CIPP, horizontal directional drilling (HDD) standards in place by the ASTM are for operation practices, not manufacturing design. ASTM F1962-11 outlines the rules required for Maxi-Horizontal Directional Drilling. Maxi drill equipment is categorized as drilling of boreholes up to several thousand feet in length and laying pipes up to 48-inches or greater in diameter at depths of up to 200-feet.
ASTM F1962-11 outlines preliminary site investigation, safety and environment, path layout designs, site cleanup and damage preventions. It also provides a rational, analytical method for polyethylene pipe selection.
ASTM International has 232 standards covering 14 different areas for pipelines. Trenchless technology plastic pipe uses the account for 25 of those standards. These standards include the installation of liners, replacement pipes and grout-in-place systems.
While there are numerous testing practices pipe manufacturers must pass for their product to achieve ASTM certification, there are four standards all trenchless plumbing must achieve. The Darmstadt Abrasion Resistance test evaluates the abrasion resistance of a pipe section. Testers fill a semi-circular pipe section with gravel, sand and water and repeatedly tilt it for a predetermined number of cycles. Workers then analyze the wear to determine durability.
Newly installed lines must pass a pressure test to determine the integrity of the pipeline. The pressure test may be hydrostatic or pneumatic. Hydrostatic tests consist of clearing the section of all product customarily transported. It is then filled with water to 125% of maximum operating pressure and remains at this level for 4 to 6-hours.
Pneumatic testing is similar. However, instead of filling the section with water it is filled with an inert gas.
OSHA and Trenchless Technology
As part of the Department of Labor, the Occupational Safety and Health Administration, OSHA, regulates the standards for a healthy and safe work environment. OSHA provides training and education for businesses to adhere to their strict guidelines.
Like all sectors, trenchless technology has unique set or regulations to help keep workers safe while on the job.
Basic Safety Requirements
To adhere to safety requirements, OSHA suggests that before operating any machinery, workers read the operator’s manual for their specific equipment. They also recommend any training on how to use the mechanism available before beginning work.
Before beginning work, OSHA regulation stipulates a geotechnical survey be performed in the work area to determine the soil type and bearing capacity.
When working with rotary machines, such as drills, workers must stay clear of all rotating heads, augers, and pipes. OSHA also stipulates loose-fitting clothing, loose long hair and jewelry may be hazards when working near these machines, as these items may get caught in the moving parts.
Workers near the machine should not step over, on or straddle the auger or shaft. OSHA also mandates that if pipe connection or disconnection is needed while the drill is in motion, the use of an extremely slow speed and pipe tongs is required. However, it is recommended that the auger not be in action during the connection/disconnection process.
While trenchless projects do not have the open trenches of traditional underground operations, there are times when a boring pit may be necessary. If required, the cavity must be large enough for the equipment and for workers to safely move around. The use of trench boxes helps to ensure structural stability of the pit. Additionally, OSHA requires a safety zone for hoisting items in and out of the hole.
Also, pits may contain a hazardous atmosphere due to the equipment use. Evaluating the atmosphere within a pit using gas monitors is essential. Low oxygen levels, dangerous gasses, such as carbon monoxide, hydrogen sulfide, and flammable gasses pose significant safety risks to workers in the pit.
Important Contact Information
If you have questions about ASTM Internationals testing guidelines or want more information on specific standards, you can visit their website at www.astm.org.
ASTM headquarters are located at 100 Barr Harbor Drive P.O. Box C7100 West Conshohocken, PA 19428-2959, USA. The ASTM headquarter telephone number is +1(610)832-9500, and their fax is 1(610) 832-9555. You can email them at [email protected] or fill out their contact form on their website.
In the event of an emergency or to report unsafe working conditions you can contact the Occupational Safety and Health Administration at 800-310-6742. You can also find your local OSHA office by visiting their website www.osha.gov or by clicking here.
Referring to the many ASTM International standards testing and OSHA’s regulation for worksite safety can help ensure the equipment used is safe.