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Engineering Pipe & Casing Specification Guide

Specify PVC/PVC-U, ABS inclinometer casing, PE/HDPE and custom perforated pipe systems with practical guidance on dimensions, SDR, joints, slots, tolerances, QA/QC, documentation and project-specific requirements.

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Specification Fundamentals

A good specification defines performance before it defines a product.

PVC/PVC-U pipe, ABS inclinometer casing, PE/HDPE engineering pipe and custom perforated pipe perform very different functions. A procurement specification should therefore define application, geometry, material, loading, connections, tolerances, environment and verification requirements before a supplier is asked to quote.

01

Application

Define what the pipe actually does: monitoring casing, groundwater well, dewatering pipe, pressure pipe, drainage, screen, intake or another engineered function.

02

Performance

State the relevant structural, hydraulic, dimensional, chemical, temperature and monitoring requirements instead of relying only on a nominal diameter.

03

Interface

Specify joints, couplings, fittings, end caps, probes, pumps, filters and other interfaces that determine whether individual pipe sections form a working system.

04

Verification

Define tolerances, inspections, certificates, test records, samples or other documentation required before production and delivery.

Specification rule: avoid copying a competitor’s catalogue dimensions into a project specification unless those dimensions are genuinely required. Specify the engineering outcome first, then define mandatory dimensions and tolerances.

Key Parameters

The parameters that should appear on an engineering pipe schedule.

Not every parameter applies to every product. The specification should identify which characteristics are mandatory, which are nominal and which must be demonstrated by manufacturer data or project-specific testing.

Parameter Why It Matters Typical Relevance
Material / Resin Defines the basic polymer system and establishes the starting point for mechanical and chemical performance. PVC/PVC-U, ABS, PE/HDPE, all custom products
OD / ID Controls interfaces, borehole clearance, probe access, hydraulic area and connection compatibility. All products
Wall Thickness Affects stiffness, pressure capability, collapse behaviour, weight and remaining strength after perforation. PVC, PE/HDPE, ABS, screens
SDR / Pressure Class Defines dimensional relationship and pressure-system requirements where applicable. Primarily PE/HDPE and pressure PVC-U
Length Influences transport, installation rate, number of joints and site handling. All products
Connection Determines alignment, sealing, tensile continuity, pressure integrity and installation method. All sectional systems
Tolerance Controls interchangeability and dimensional consistency rather than merely stating a nominal size. All engineered products
Slot / Hole Geometry Controls particle retention, hydraulic entry and remaining structural area. Perforated pipe and well screen
Groove Geometry & Spiral Influences probe orientation and measurement quality in inclinometer installations. ABS inclinometer casing
Environmental Conditions Temperature, UV, chemicals, saline water and contaminated ground may influence material selection. All products

PVC / PVC-U Specification

Specify PVC pipe by application, geometry, loading and joint—not colour alone.

PVC/PVC-U systems can serve groundwater monitoring, well casing, dewatering, drainage and pressure-water applications. The required specification changes substantially between a monitoring well screen and a pressure pipeline.

Dimensions

  • Nominal size and actual OD where required
  • Minimum or nominal wall thickness
  • Internal clear diameter
  • Section length
  • Dimensional tolerances

Mechanical Requirements

  • Pressure class where applicable
  • Collapse requirement for well casing
  • Joint tensile / stripping requirement where relevant
  • Installation depth and imposed loads
  • Temperature conditions

Well & Screen Requirements

  • Plain casing or screened section
  • Slot width and tolerance
  • Screen length
  • Open-area requirement
  • Thread or approved connection
For pressure water applications, ISO 1452 is one relevant international standards family for PVC-U systems. A groundwater screen or monitoring casing, however, should not automatically be specified as though it were a pressure-water pipe; its functional requirements are different.

ABS Inclinometer Casing

For inclinometer casing, measurement geometry is part of the specification.

ABS inclinometer casing is not simply a plastic tube. Its grooves provide the orientation reference for an inclinometer probe, so groove continuity, spiral, clear internal geometry and connection alignment directly affect the monitoring system.

Tube Geometry

State OD, ID, casing length and any coupling OD restrictions required by borehole diameter or installation method.

Four Grooves

Define the required orthogonal guide-groove arrangement and compatibility with the intended inclinometer probe or in-place sensor system.

Groove Spiral

Specify the allowable spiral or twist over a defined casing length. Do not describe the casing only by diameter.

Joint System

Define standard coupling, telescopic section, flush/self-aligning or other approved connection and the required sealing arrangement.

Specification Item Recommended Project Definition
Material ABS grade / manufacturer specification required by the project
Outside Diameter Nominal plus applicable tolerance
Inside / Clear Diameter Sufficient for the nominated probe or IPI system
Groove Configuration Four longitudinal orthogonal guide grooves
Groove Spiral Maximum allowable angular deviation over a stated length
Connection Coupling and alignment method explicitly identified
Sealing Method for limiting grout / water ingress where required
Collapse / Structural Requirement Define where installation pressure or grouting conditions make this relevant
Temperature Maximum expected storage, installation and service conditions
ISO 18674-3:2017 covers geotechnical monitoring by inclinometers and remains current. Project specifications should align casing requirements with the complete monitoring method rather than treating the casing as an isolated commodity.

PE / HDPE Specification

For PE pipe, SDR is useful—but SDR alone is not a complete specification.

A PE/HDPE engineering pipe specification should identify the material designation, dimensional series, operating duty, joining method and environmental conditions. For pressure applications, these parameters must be evaluated as a system.

Geometry

OD, Wall & SDR

SDR expresses the relationship between nominal outside diameter and nominal wall thickness. State the required pipe series or dimensions together with the governing specification.

Duty

Pressure & Temperature

Operating pressure, design conditions, fluid, temperature and transient loading should be defined rather than selecting an SDR number without service context.

System

Jointing & Fittings

Define butt fusion, electrofusion, mechanical transition or other approved connections and ensure fittings are compatible with the specified pipe system.

ISO 4427-1 and ISO 4427-2:2019 are relevant to PE piping for water supply and drainage/sewerage under pressure. ISO 4427-2 specifically notes intended uses including sea outfalls and pipes laid in water. Always confirm the applicable project, national and client standards.

Perforated & Slotted Pipe

“Perforated pipe” is not a specification.

A fabrication drawing should define exactly where water or groundwater is intended to enter or leave the pipe. Hole or slot geometry, spacing, pattern and total perforated interval can materially change hydraulic behaviour and remaining pipe strength.

Opening Type

State circular hole, machined slot or another approved geometry.

Opening Size

Define slot width or hole diameter together with the required manufacturing tolerance.

Pattern

Define number of rows, circumferential spacing, longitudinal pitch, orientation and stagger where applicable.

Perforated Zone

Identify exact screened length, blank sections and distance from pipe ends or connections.

RFQ Parameter Example of What to State
Base Pipe Material, OD, wall thickness / SDR and length
Opening Slot width × slot length, or hole diameter
Tolerance Permitted dimensional deviation
Rows Number and angular orientation
Pitch Longitudinal and circumferential spacing
Screen Interval Start and end position of perforation
Open Area Required percentage or calculated target where relevant
Ends Plain, threaded, fused, capped or project-specific
More open area is not automatically better. Increasing the number or size of openings can improve hydraulic entry while reducing the remaining structural section. The final pattern should reflect both hydraulic and mechanical requirements.

Connection Specification

Specify the joint as carefully as the pipe.

Many installation problems occur at interfaces rather than in the pipe wall. Connection geometry, sealing, alignment and installation procedure should therefore be part of the procurement specification.

ABS Casing Connections

Specify groove alignment, coupling geometry, telescopic requirements and grout/water sealing. Push-fit or self-aligning systems should still have measurable acceptance requirements.

PVC Connections

Threaded, solvent-welded or other project-approved joints should be selected around tensile, sealing, installation and well-depth requirements.

PE / HDPE Connections

Specify fusion or mechanical connection procedures, compatible fittings and any project-required qualification, inspection or joint records.

Standards Framework

Use standards by scope—not by keyword.

A standard that applies to pressure-water pipe does not automatically govern an inclinometer casing or custom groundwater screen. The designer should identify the function first and then select the applicable international, national, client and project requirements.

Reference Relevant Scope Specification Use
ISO 18674-3:2017 Geotechnical monitoring — measurement of displacements across a line using inclinometers. Relevant framework when specifying an inclinometer monitoring system and its casing requirements.
ISO 4427 Series PE piping systems for water supply and drainage/sewerage under pressure. Relevant to qualifying applicable PE pressure-pipe systems, dimensions, materials and system components.
ISO 1452 Series PVC-U piping systems for water supply and pressure drainage/sewerage. Relevant where the intended PVC-U application falls within the standard’s scope.
Project / National Standards Owner, authority, country and application-specific requirements. May supplement or supersede generic catalogue requirements and should be stated directly in the RFQ.
Important: standards are revised. The purchaser and designer should verify the current edition and amendments at the time of specification. GEOLUR can review a supplied project specification, but the governing design standard remains a project responsibility unless otherwise agreed.

QA / QC

Turn specification language into inspectable requirements.

A requirement has limited procurement value if neither purchaser nor supplier can determine whether the delivered product complies. GEOLUR therefore recommends defining measurable acceptance points before production.

  • Material / resin identification
  • Outside diameter verification
  • Inside diameter where critical
  • Wall-thickness verification
  • Length tolerance
  • SDR / dimensional series where applicable
  • Connection geometry
  • Joint fit and alignment
  • Inclinometer groove geometry
  • Groove spiral requirement
  • Slot width / hole diameter
  • Perforation pitch and pattern
  • Screened interval
  • Visual workmanship
  • Required markings
  • Specified documentation
For custom-manufactured products, approve the drawing and acceptance criteria before mass production. This is generally more effective than attempting to resolve an ambiguous dimensional requirement after the goods reach site.

Specification Workflow

From engineering requirement to a quote-ready specification.

A concise specification can still be technically complete. GEOLUR recommends resolving the requirement in five stages.

Step 1

Define Function

Monitoring, pressure conveyance, well casing, dewatering, drainage, intake or custom screening.

Step 2

Define Environment

Depth, soil, groundwater, chemistry, temperature, UV, loading and installation constraints.

Step 3

Define Geometry

Material, OD, ID, wall, SDR, length, grooves, slots, holes and connection configuration.

Step 4

Define Acceptance

Tolerances, testing, inspection, certificates, drawings, markings and documentation.

Then request the quote. Once these parameters are clear, competing quotations can be compared on substantially more meaningful technical terms.

RFQ Specification Checklist

Send GEOLUR enough information to quote the right product the first time.

For standard or custom supply, attach the project specification and drawings whenever available. If no formal specification exists, the following information provides a practical starting point.

Technical Information

  • Product application
  • Required material
  • OD / nominal diameter
  • ID where critical
  • Wall thickness / SDR
  • Pressure class where applicable
  • Section length
  • Connection type
  • Required standards
  • Operating / installation environment

Custom Details

  • Groove requirements for inclinometer casing
  • Slot width or hole diameter
  • Perforation pattern
  • Screened interval
  • Accessories and end caps
  • Required tolerances
  • Inspection / documentation requirements
  • Total quantity
  • Delivery country and destination
  • Required delivery schedule
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GEOLUR Product Families

One specification framework. Different engineering functions.

GEOLUR supplies engineering pipe and casing products across four core families. Each should be specified according to its actual project function rather than treated as an interchangeable plastic tube.

PVC / PVC-U Monitoring Pipes

For groundwater, monitoring, well, dewatering and related engineered applications requiring rigid polymer casing or screen configurations.

ABS Inclinometer Casings

Precision grooved casing for geotechnical deformation monitoring where probe guidance, groove continuity and dimensional control are fundamental.

PE / HDPE Engineering Pipes

Engineering pipe systems where toughness, flexibility, pressure duty, corrosion resistance or fusion-jointed configurations are required.

Custom Perforated Pipe Systems

Project-defined slot, hole, spacing and screened-zone configurations developed around hydraulic and structural requirements.

Specification FAQs

Common questions when specifying engineering pipe and casing.

What information should a pipe specification include?
At minimum, define application, material, dimensions, wall thickness or dimensional series, section length, connection, environmental conditions, relevant standards, tolerances and required documentation. Specialist products require additional parameters.
Is nominal pipe diameter enough for an RFQ?
Usually not. OD, ID and wall thickness can matter for different reasons, and products described by the same nominal size are not necessarily dimensionally interchangeable. State the controlling dimensions or governing standard.
What does SDR mean for PE or HDPE pipe?
SDR is a dimensional ratio relating nominal outside diameter to nominal wall thickness. It is useful when defining PE pipe geometry, but material designation, pressure and temperature requirements, joining method and governing standard must also be considered.
What should be specified for ABS inclinometer casing?
Typical requirements include material, OD, ID, casing length, groove geometry, allowable groove spiral, connection and alignment system, sealing, structural requirements where relevant and compatibility with the intended probe or in-place inclinometer system.
Why does groove spiral matter in inclinometer casing?
The grooves provide an orientation reference for the probe. Excessive rotation of those grooves along the casing can affect the relationship between probe orientation and the intended measurement axes, so spiral is a meaningful casing quality parameter.
How should a perforated pipe be specified?
Define the base pipe first, then specify opening type, slot width or hole diameter, tolerances, number of rows, spacing or pitch, orientation, perforated interval, required open area where applicable, and connection or end details.
Should I specify the international standard or exact dimensions?
Often both are useful. A governing standard establishes a technical framework, while project-critical dimensions, interfaces and performance requirements should still be stated explicitly. Do not assume that citing a standard resolves every project-specific interface.
Can GEOLUR manufacture to a project-specific specification?
GEOLUR can review project-specific pipe, casing and perforation requirements for manufacturing and supply feasibility. Send the governing specification, drawings, quantities and required documentation with the RFQ.

Specify with GEOLUR

A clearer specification produces a better technical comparison.

GEOLUR approaches PVC/PVC-U, ABS, PE/HDPE and custom perforated pipe procurement from an engineering-specification perspective. Send your drawings, bill of quantities or project requirements and we can review the requested configuration for quotation.

Engineering Context

Product selection starts from the application, interfaces and installation environment rather than a generic pipe description.

Custom Configuration

Dimensions, connections, perforation and accessories can be reviewed against project-specific requirements and manufacturing feasibility.

Quote-Ready Scope

A defined technical schedule reduces ambiguity between requested product, manufactured product and delivered product.

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