Learn how to select and maintain instrumentation manifolds according to ISO 15848 and API 6D. Technical guide from ZAES, a leading manufacturer of industrial valves.

1️. Introduction: why manifolds are key to industrial instrumentation:

In any industrial installation - be it a oil and gas, petrochemicals, energy o water treatment-The instrumentation manifolds are essential components.
Its main function is to isolating, purging and calibrating measuring instruments (such as pressure transmitters or flowmeters) without interrupting the process.

At ZAESas manufacturer of industrial valves and manifolds with decades of experience, we've put together this technical guide to help you to choosing, installing and maintaining correctly an instrumentation manifold.

Here you will find selection criteria, preventive maintenance, suitable materials and international standards that guarantee the safety and reliability of the system.

2️. What is an instrumentation manifold:

A instrumentation manifold is a set of interconnected valves to control the flow of fluids to a measuring instrument.
It aims to facilitate operations such as:

• Isolation of the instrument without stopping the process line.
• Purging or draining
• Pressure calibration and equalisation.
• Maintenance or replacement of measuring equipment.

3️. Manifold types: 2, 3 and 5 valves:

- 2-valve manifold

• Used in measurements of static pressure or level.
• It consists of an isolation valve and a bleed valve.
• Ideal for pressure transmitters in general applications.

- 3-valve manifold

• Designed for differential pressure.
• It includes two isolation valves and one equalisation valve.
• Allows calibration without disassembling the instrument, balancing both pressure lines.

–  5-valve manifold

• Recommended when the following are required frequent calibrations.
• It has two isolation valves, one equalisation valve and two purge valves.
• Facilitates maintenance and cleaning tasks in complete safety.

4️. Most commonly used materials:

ZAES Council: for services with H₂S or corrosive environmentsAlways check the compatibility of the material with the standard. NACE MR0175 / ISO 15156.

5️. Technical standards to be met by an industrial manifold:

Complying with international standards ensures the safety, watertightness and reliability of valves and manifolds.
These are the most relevant in the sector:

• ISO 15848 → Fugitive emissions in industrial valves.
• API 6D → Design and testing of oil and gas pipeline valves.
• EN 12266-1 / ISO 5208 → Tightness tests and acceptance criteria.
• MSS SP-99 → Manifolds and instrumentation valves: pressures, connections and sizes.

6️. How to choose the right manifold:

Before defining the model, analyse:

1. Type of measurement → static or differential.
2. Working pressure and temperature.
3. Type of fluid (gaseous, liquid or corrosive).
4. Mounting configuration (direct to transmitter or remote with tubing).
5. Applicable standards to the project (API, ISO, PED, ATEX, etc.).

Pro tip: an oversized manifold or a manifold with unsuitable material can lead to leaks, loss of accuracy or maintenance cost overruns.

7️. Preventive maintenance and good practice:

Regular maintenance prevents leaks, failures and downtime.
ZAES recommends:

• Visual inspection every 6 months.
• Tightness tests in accordance with EN 12266-1.
• Cleaning of internal ducts and verification of entries.
• Lubrication of stems and seals with compatible products.
• Replacement of seals and components according to preventive plan.

In addition, in critical processes, it is advisable to perform a transmitter calibration after any intervention on the manifold.

8️. Safety and environment: fugitive emissions:

The fugitive emissions are small leaks of gases escaping through gaskets or joints.
Complying with the standard ISO 15848 ensures that the ZAES manifolds and valves reduce these emissions, contributing to the sustainability and environmental safety.

9️. ZAES: experience and reliability in industrial valves:

With more than 50 years of experience, ZAES is positioned as European benchmark for industrial valves and instrumentation manifolds.
The company offers solutions designed and manufactured to the highest standards of quality, combining in-house engineering, European production y personalised technical advice.

In a market where giants such as Emerson (Fisher), Flowserve, Valmet (Neles), KSB o SwagelokZAES stands out for its proximity, flexibility and speed of supply -in addition to its commitment to certified quality.

10️. Conclusion: precision, security and confidence:

Selecting the right manifold is more than a question of a catalogue:
is a technical decision that has a direct impact on the safety, efficiency and maintenance of the entire plant.

With this guide, ZAES reaffirms its commitment to the precision engineeringthe operational reliability and the customised technical support.