Central Air Preparation vs Point-of-Use FRL: Map the Boundaries

Compare responsibilities before comparing the number of FRLs

Central treatment serves an agreed shared supply boundary; point-of-use treatment addresses the requirements of a particular branch or consuming device. They need not be competing whole-system choices. Parker’s guidance separates the air-quality requirement leaving the compressor room from requirements at each point of use. It recommends reviewing treatment before distribution and at critical applications. [1] The purchasing question is therefore which requirements can share a treatment duty and which remain specific to one user. A count of filters or regulators cannot answer that question.

• Choose the required air-preparation functions first

Name the shared and local boundaries on the same drawing

Give the shared supply handover a reference such as S0, and give every relevant user its own reference, such as A1, B1 and C1. Mark the existing treatment, distribution route, branch take-offs and actual point at which the equipment requirement applies. These references are document labels, not pressure taps or a proposed engineered layout. Record who supplies the air at each boundary and what evidence describes its condition. Do not use a compressor-room result as the unqualified acceptance result for a remote machine. Parker notes the role of point-of-use purification in dealing with contamination associated with distribution. [1, 2]

A hypothetical three-branch requirement map

Assume a project brief contains three different requirements: Machine A prohibits added lubricant, Tool B requires external oil-mist lubrication, and Process C has a separate air-quality specification that has not yet been supplied. These are hypothetical inputs, not claims about a customer installation or universal rules for those equipment types. The topology for discussion is an existing shared treatment boundary S0, followed by distribution that divides into A, B and C. No sizes, pressures, treatment sequence or isolation hardware are selected by this example.

Keep intentional oil addition inside the approved user’s requirement

In this example, adding a lubricator on the shared path before the split would also introduce oil toward users A and C. That conflicts with the stated requirement for A and leaves C unresolved. Ask the designer to place any intentional lubrication within the approved branch arrangement and check the whole path. Festo recommends locating a lubricator near the consuming device where possible to avoid unnecessarily carrying oil through the system. [3] This is a general principle, not a connection drawing for XMC products. A downstream mist separator is not an automatic permission to lubricate a shared line or a guarantee that an added-oil requirement has been reversed.

• Separate oil-mist treatment from other filtration duties

Separate the shared pressure condition from each user’s setting

Enter the available pressure at the shared boundary and the required pressure at each consuming point as different fields. If users need different settings, have the supplier review the relevant branch regulation instead of treating one central setting as proof that all users are satisfied. Festo discusses additional regulation for applications with differing pressure needs. [3] The branch review still needs the actual demand and pressure available during operation. This map does not select a regulator, approve two regulation stages in series or prescribe one pressure for the shared main.

• Size the shared and local paths against actual demand
• For large-port HA component selection, use the distribution-branch brief

Allocate extra treatment without duplicating an unexplained stage

For each proposed local stage, state which requirement it addresses and what upstream condition it needs. Identify the evidence that the existing shared treatment does or does not provide. If the requirement concerns water vapour, oil content or particles, keep those fields separate and use the relevant treatment review. Do not add another identical filter at every machine merely because a box on the drawing is labelled FRL. Equally, do not remove local treatment solely because central equipment exists. The decision must close a documented requirement at the consuming boundary.

• Review water appearing downstream of a filter

Choose XMC functions after the boundary decisions

The XMC catalogue identifies HAF filtration, HAR regulation and HAL lubrication as separate large-port component functions. The HDA pages distinguish HDAF filtration, HDAR regulation, HDAL lubrication and combined HDAW filtration/regulation; HDAFM is a separate mist-separator family. [4-7] These are candidate functions, not a rule that HA belongs centrally and HDA belongs at a machine. Match the proposed unit and arrangement to its duty, complete model, connection, operating data and service access. An HDAW label does not establish a complete air-quality class, and the HDAFM selection does not supply a dryer dew-point guarantee.

• HA product family
• HAF large-port filtration
• HAR large-port regulation
• HAL lubrication when required
• HDA component functions
• HDAW filter-regulators
• HDAFM mist-separator reference

Assign service and acceptance responsibility at each handover

For the proposed arrangement, identify who checks the shared treatment, who checks each local unit and who accepts the delivered condition. Mark which users could be affected by maintenance or a change of route. A local treatment position does not itself establish independent isolation; the machine’s approved procedures govern service. Keep a change to a shared stage, bypass route or lubrication arrangement visible to the responsible downstream users. The worksheet below is a suggested project record, not a mandated maintenance interval or a complete commissioning procedure.

Send a requirement map with the quotation request

Send the boundary drawing and both worksheets together. Attach the actual machine air-quality and lubrication documents, supply and demand information, current models and proposed purchasing scope. Label assumed, measured and unknown inputs. Ask XMC to review the relevant component functions and arrangement, while the plant-air and application suppliers close their own specification and acceptance items. Where Process C’s requirement remains missing, preserve that dependency rather than borrowing a purity class or selecting its treatment from another branch.

• Request a shared and point-of-use air-treatment review

Catalogue and technical references

The branch map and responsibility worksheet are illustrative purchasing tools. They do not specify a complete engineered system, tested layout or measured energy saving. External guidance supports general distribution, regulation and lubrication principles. Its air-quality classes, equipment sequences, performance and maintenance limits are not assigned to XMC products.

• [1] Parker GSFE catalogue, printed pages 5 and 8: shared and point-of-use requirements
• [2] Parker OIL-X user guide, printed page 5: distribution and point-of-use treatment
• [3] Festo air-preparation white paper, printed pages 9 and 13
• [4] XMC HA catalogue, printed pages 24-28
• [5] XMC HAF catalogue, printed page 29
• [5] XMC HAR catalogue, printed page 30
• [5] XMC HAL catalogue, printed page 31
• [6] XMC HDA catalogue, printed pages 48-59
• [7] XMC HDAFM catalogue, printed page 60