Sample Probe Assemblies — Custom Engineered for Your Process
Custom sample probe assemblies with probe tubes from 1/4 to 1 inch OD in 304 SS, 316 SS, 316 NACE, Monel 400, Hastelloy C22/C276, and Inconel 600. Fixed, retractable, flanged, and threaded configurations for pipeline sampling.
Sample Probe Assemblies
Our sample probe assemblies are precision-engineered instrumentation systems designed to extract representative samples from pressurized pipelines and process vessels. Each assembly is custom-built to your specific process conditions — pressure, temperature, pipe diameter, flow velocity, and chemical environment — ensuring safe, reliable, and accurate sampling for the life of the installation.
Every assembly undergoes a full engineering review including wake frequency analysis per ASME PTC 19.3 TW-2016, pressure rating verification per Barlow's formula, and material compatibility assessment for the specified process chemistry.
Standard Configurations
Each sample probe assembly includes:
- Probe tube: Seamless instrumentation tubing per ASTM A213 / A269 (stainless steel) or applicable ASTM specification (exotic alloys)
- Packing gland: Conax Technologies PG-series compression fitting with appropriate sealant
- Isolation valve: 316 SS needle valve or ball valve rated for the operating pressure and temperature
- Stop collar: 316 SS set-screw retaining collar
- Retaining chain: 316 SS safety chain with attachment hardware
- Documentation: Material test reports (MTRs), wake frequency analysis report, dimensional drawing
Probe Tube Specifications
Standard Tube Sizes
| Tube OD | Wall Thickness | Bore ID | Material Options | Working Pressure (316 SS, 70 degF) |
| 1/4" (0.250") | 0.035" | 0.180" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 4,700 psi |
| 1/4" (0.250") | 0.049" | 0.152" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 6,700 psi |
| 3/8" (0.375") | 0.035" | 0.305" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 3,100 psi |
| 3/8" (0.375") | 0.049" | 0.277" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 4,400 psi |
| 1/2" (0.500") | 0.035" | 0.430" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 2,300 psi |
| 1/2" (0.500") | 0.049" | 0.402" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 3,300 psi |
| 1/2" (0.500") | 0.065" | 0.370" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 4,400 psi |
| 3/4" (0.750") | 0.049" | 0.652" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 2,200 psi |
| 3/4" (0.750") | 0.065" | 0.620" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 2,900 psi |
| 3/4" (0.750") | 0.095" | 0.560" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 4,300 psi |
| 5/8" (0.625") | 0.065" | 0.495" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 3,500 psi |
| 1" (1.000") | 0.120" | 0.760" | 304 SS, 316 SS, 316 NACE, Monel, C-276, C-22, Inconel 600 | 4,000 psi |
Material Details
| Material | UNS Number | Max Temp | Sour Service (NACE) | Best For |
| 304 SS | S30400 | 1,500 degF | No | Clean, non-corrosive service |
| 316 SS | S31600 | 1,500 degF | No (standard) | General-purpose sampling |
| 316 SS NACE | S31600 | 1,500 degF | Yes (MR0175) | Sour gas service |
| Monel 400 | N04400 | 1,000 degF | Conditional | HF service, seawater |
| Hastelloy C-276 | N10276 | 1,250 degF | Yes | Aggressive acids, chlorides |
| Hastelloy C-22 | N06022 | 1,250 degF | Yes | Mixed/variable chemistry |
| Inconel 600 | N06600 | 2,000 degF | No | High-temperature service |
Surface Treatments and Coatings
| Treatment | Description | Application |
| Mill finish | Standard as-received finish | General process sampling |
| Electropolished | Electrochemically smoothed to less than 15 Ra | Low-ppm sulfur and moisture |
| SilcoNert 2000 | CVD inert coating, interior bore | Trace ppb-level H2S, sulfur, mercury |
| SilcoNert 1000 | CVD coating for corrosion resistance | Corrosion protection, moderate inertness |
| Full coating details |
Probe End Types
Five standard end configurations are available, each suited to different sampling requirements. For a detailed comparison, see our probe end types guide.
- Plain end: Standard flat cut; clean, simple opening suitable for gas service
- Plain end with laser markings: Flat cut with orientation marks for precise rotational positioning during installation
- V-notch cut: Angled cut (15-90 degrees, typically 45 degrees) that reduces particulate entry and directs sample flow; configurable on up to 4 sides (front/upstream, back/downstream, left, right)
- Integral NPT: Threaded pipe connection machined directly into the probe tip; used for connecting downstream sample conditioning equipment
- Tube end fitting NPT: Compression fitting at the probe tip; provides a removable connection point for flexible downstream tubing
Cut Configuration
V-notch and plain laser cuts can be applied to multiple sides of the probe tube:
| Cut Side | Orientation | Purpose |
| Front (upstream) | Faces the process flow | Maximum sample capture from flowing stream |
| Back (downstream) | Away from process flow | Reduced velocity, lower particulate ingestion |
| Left | 90 degrees to flow | Cross-stream sampling |
| Right | 90 degrees to flow | Cross-stream sampling |
Cut angles range from 15 degrees to 90 degrees, with 45 degrees being the standard for most applications.
Applications
- Oil and gas pipeline sampling — natural gas, crude oil, NGL, produced water
- Pharmaceutical sampling — USP water, sterile processes, clean sampling
- Chemical processing — reactor effluent, intermediate product, raw material verification
- Power generation — steam purity, feedwater chemistry, flue gas
- Environmental monitoring — CEMS stack sampling, ambient air quality
Documentation and Quality
All assemblies are supplied with:
- Dimensional drawing showing tube length, insertion depth, and overall assembly dimensions
- Wake frequency analysis report per ASME PTC 19.3 TW-2016
- Material test reports (MTRs) per EN 10204 Type 3.1 for all wetted components
- Hydrostatic or pneumatic test certificate (when specified)
- NACE MR0175 compliance documentation (when applicable)
How to Order
To specify a sample probe assembly, provide:
1. Pipe size, schedule, and material
2. Operating pressure and temperature (normal and maximum)
3. Process fluid composition (include H2S, CO2, chloride content)
4. Flow velocity (normal and maximum)
5. Required insertion depth or pipe ID (we calculate the optimal depth)
6. Process connection type and size (weldolet, threadolet, flange)
7. Desired probe tube material and OD
8. Coating requirements (if any)
9. Applicable codes and standards (NACE, ASME, client specifications)
Contact our engineering team for a quote and technical review of your application.