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D4064-01 – Standard Test Method Technical Guide
📋 Scope and Applicable Species
This practice covers the full-length preservative treatment of utility poles by the thermal process. It applies specifically to poles made from the following species:
| 🟦 Species | 📏 Scientific Name |
|---|---|
| Douglas fir | Pseudotsuga menziesii |
| Lodgepole pine | Pinus contorta |
| Alaska yellow cedar | Chamaecyparis nootkatensis |
| Northern white cedar | Thuja occidentalis |
| Western red cedar | Thuja plicata |
💡 Note: Requirements may vary within and between species. Carefully select options based on intended use and service area.
Purchasers should note that requirements vary both within and between species, and care must be used in selecting specific options for the intended use and service area.
🔥 Treating Process and Temperature Control
The thermal treating process consists of at least two operations: a hot cycle and a cold or cooling cycle. The cold cycle involves replacing hot preservative with cooler preservative, while the cooling cycle allows the hot preservative to remain in the tank and cool naturally or via a heat exchanger. An optional final expansion cycle with hot preservative may be applied.
During the entire process, the temperature of the preservative must not exceed 230°F (110°C).
⚠️ Temperature Limit: Never exceed 230°F (110°C) during any cycle to ensure treatment effectiveness and safety.
⚙️ Equipment and Pretreatment Requirements
Treating plants must be equipped with thermometers, gages, clocks, recording devices, and related items to accurately indicate and record conditions at all stages. Such equipment shall be maintained in acceptable working condition and inspected for calibration annually.
| 🛠️ Equipment | 🎯 Requirement |
|---|---|
| Thermometers | Indicate temperature accurately |
| Gages | Measure pressure or other parameters |
| Clocks | Timing of process cycles |
| Recording devices | Document process conditions |
Before treatment, poles shall be air seasoned or kiln dried under proper sanitary conditions, as defined in ANSI 05.1, Paragraph 5.1.2.1 and 5.1.2.3, to minimize checking after treatment and permit maximum preservative penetration. Additionally, the apparatus and chemicals necessary for making analyses and tests must be provided by plant operators and kept in condition for use at all times.
❓ Frequently Asked Questions
🔍 What is the purpose of the thermal process?
The thermal process ensures full-length preservative treatment of utility poles to protect against decay and extend service life.
💡 What is the maximum temperature allowed?
The preservative temperature must not exceed 230°F (110°C) during any part of the process.
⚡ Which wood species can be treated?
The standard covers Douglas fir, Lodgepole pine, Alaska yellow cedar, Northern white cedar, and Western red cedar.
📌 What are the seasoning requirements before treatment?
Poles must be air seasoned or kiln dried as per ANSI 05.1 to minimize checking and maximize preservative penetration.