Globe and control valves

Globe valves regulate flow through movement of a plug relative to a seat. Control valves combine a selected valve body and trim with an actuator and control accessories to regulate a process variable.

Typical applications

Pressure, flow, temperature and level control loops use control valves. Multiple operating cases are needed to assess both normal regulation and limiting conditions.

Types and configuration choices

Body pattern, trim characteristics, actuator and positioner should be evaluated together. Pressure drop, fluid properties, noise, cavitation and the required fail position influence selection.

Specify the regulating assembly behind each valve tag

State whether the enquiry is for a manually operated globe valve, a complete actuated control valve or a replacement part for an existing assembly. A globe body describes construction, while a control-valve enquiry must also describe the regulating function and its interfaces. Use a tag-specific datasheet so offers for a body alone are not compared with offers including an actuator, positioner and accessories. Identify which parts will be retained and who is responsible for integrating them.

For a replacement, provide the existing body, trim, actuator and instrument identification together with a controlled drawing and current operating cases. Clarify whether the replacement is intended to reproduce the installed configuration or resolve a changed process requirement. A matching model description or face-to-face dimension does not confirm equivalent regulating performance. Ask a proposed alternative to state its assumptions, interface differences and review evidence without treating a lower price as approval to change the assembly.

Review the proposal against a common operating-case register

Give every operating case a reference that can be carried into the sizing response and technical comparison. Ask the response to identify the proposed body and trim, the calculation basis and the case-specific findings that the project needs reviewed. Keep unresolved input data visible. If bidders use different assumed pressures or fluid properties, reconcile those assumptions before comparing the results; a neatly presented calculation is still conditional on the data used.

Where the documented duty requires review of noise, cavitation, flashing or other limiting behavior, ask for the applicable assessment and the conditions it covers. Separate a selected trim arrangement from evidence that it addresses the actual cases. The responsible engineering reviewer should identify any additional system information or specialist study required. This enquiry guidance does not prescribe a valve size, trim selection, acceptable travel band or adjustment procedure, and it does not guarantee stable control from a catalogue description.

Separate factory evidence from installed control-loop acceptance

List the required factory inspection, pressure-boundary, closure and assembly-function records with their acceptance basis. Ask each record to identify the configuration and tag examined. A workshop demonstration of valve movement is different from verification of the installed loop's performance, so show site configuration and commissioning responsibilities as separate scope items. Identify who supplies the process inputs, interface checks and approved test arrangements needed at each stage, including any items excluded from an equipment-only offer.

Request the final datasheet, assembly drawing, materials schedule, accessory register and configuration information needed for the owner's maintenance records. Identify spares by the offered construction and record manufacturing origin separately from the dispatch location. Keep outstanding tests, deviations and field work visible at handover. Send the controlled enquiry documents to Oillinko for manual sourcing coordination; quotations remain subject to technical review, and this page does not confirm stock, product approval or completed commissioning.

Flow cases and pressure drop

Provide a row for each required operating case, linking flow, upstream pressure, downstream pressure and temperature rather than listing unrelated maxima. Identify the units and pressure references, and distinguish measured values from design assumptions. Include minimum and normal duty alongside the maximum case when they apply. State pipe size, connection rating and any approved noise limit. Ask for a sizing response against the supplied cases, with proposed valve and trim details. Matching the line size or quoting a single flow coefficient does not establish suitability across the required operating range.

Fluid properties

Identify the fluid and its phase at the valve inlet, together with the properties needed for the applicable sizing assessment. For a liquid, provide available density, viscosity and vapour-pressure information with its temperature basis; for a gas or vapour, identify the composition and relevant property basis. Record solids or other constituents that the material and trim review must consider. Ask the engineering response to identify missing inputs and assumptions. Use the project's confirmed data rather than treating a general fluid name as a complete specification.

Required shutoff

Define the requested closure performance separately from flow-regulating duty. Identify the applicable test standard and edition, leakage requirement, test conditions and direction specified by the project. State the differential pressure to be considered when reviewing closure and actuator requirements. Ask the offer to confirm the proposed seat and trim arrangement against that basis and to list deviations. An unqualified tight-shutoff description is insufficient for comparison, and a control-valve closure test should not be interpreted as evidence that the valve fulfills a separate safety-isolation requirement.

Control signal and fail position

Provide the control-interface schedule, actuator utility conditions, required feedback and accessory scope. Distinguish the operating command from position feedback and diagnostic communications. Describe the approved response required for each relevant loss condition, such as loss of control signal, actuator supply or electrical power; do not reduce several different cases to an unexplained fail-open or fail-closed label. Request the offered assembly's stated response and verification scope. Any safety function needs its own project requirements and review; an actuator or digital positioner does not alone establish that capability.

How related requirements differ

Ball, gate and plug valves: Ball, gate and plug valves control isolation by moving a closure element across the flow path. Their internal geometry, seat design and operating mechanism affect flow resistance, sealing and suitability for the process medium. Full or reduced bore, different seat materials and manual or actuated operation are common choices. Specify size, rating, connections, temperature and required shutoff performance.

Butterfly and check valves: Butterfly valves use a rotating disc for flow control or isolation. Check valves respond to flow and pressure conditions to reduce reverse flow. These two valve families have distinct functions despite their common use in piping systems. Disc, seat and offset arrangements vary for butterfly valves. Swing, lift and dual-plate check designs require consideration of orientation, closing behavior and operating flow.

Safety and relief valves: Safety and relief valves are pressure-protection devices selected to discharge fluid under defined relieving conditions. Their capacity and configuration depend on the protected system and the approved relief design basis. Spring-loaded and pilot-operated arrangements have different characteristics. Set pressure, relieving capacity, back pressure, materials and certification requirements must be specified for the actual installation.

Compare the complete supply scope

For globe and control valves, compare the complete assembly and documented scope of supply. An offer for a component may exclude the drive, controls, fittings, accessories or inspection services needed for the installation. List exclusions and proposed alternatives so each quotation can be assessed against the same requirement. Manufacturing origin, delivery location and the supplier's business address are separate facts. If a particular origin is required, request confirmation for the actual offered item and the supporting documentation specified by your project.

Questions before requesting a quotation

What information should be available first? Start with the intended application and the current technical specification for globe and control valves. In this category, the initial review includes flow cases and pressure drop, fluid properties, required shutoff, control signal and fail position. Attach the relevant drawings or scope documents and identify any information still awaiting confirmation. This makes it possible to distinguish a preliminary enquiry from a fully defined purchasing or service requirement.

Can an alternative be accepted on size or price alone? A proposed alternative needs review against the required function, materials, interfaces and documented performance. Similar dimensions or a familiar brand name do not establish compatibility. State which requirements are mandatory and where an equivalent may be considered. Availability, lead time and supporting documents are confirmed for the actual offer rather than assumed from this catalogue.