Ball Valves · Purchase-decision comparison
Floating vs trunnion forged ball valves
Both executions are forged-body ball valves — the decision is how the ball is mounted, and that choice drives the size and pressure envelope. This table compares the two executions we publish specification pages for, using only fields that mean the same thing and are collected on the same basis for both. Where a figure is not established by the collected evidence, the cell says so and asks you to confirm it at RFQ.
Last updated: 2026-11
Comparison table
A row appears only where the field means the same thing and is collected on the same basis for both columns. A cell without collected evidence says "confirm at RFQ" — it is never filled with an assumption, and it never implies either execution cannot be supplied.
Quick decision
These conclusions apply to the two executions compared on this page — not to the ball valves family as a whole. Other executions of the same family differ, and any value marked "confirm at RFQ" is settled by the quotation, not by this table.
- Bore up to DN200, pressure to Class 2500, line pressure available to seat the ball → floating.
- Large bore (DN50–DN1400) or torque beyond the floating principle, fire-safe hydrocarbon duty → trunnion.
- The collected evidence shares one design-standards basis — the mounting principle, size band and seat compounds are the decision; unverified figures are confirmed at RFQ.
| Field | Forged Floating Ball Valve | Forged Trunnion Ball Valve |
|---|---|---|
| Working principle | ||
| Ball mounting principle The defining difference of the comparison: what carries the seating load. | Floating — line pressure seats the ball against the downstream seat; at large bore or high torque the floating principle itself becomes the limit | Trunnion-mounted — ball anchored on top and bottom trunnions so line pressure cannot push it off its seat; tight shutoff on large bore and high pressure lines |
| Ratings & size | ||
| Size range The ranges barely overlap: DN50–DN200 is common to both, above it the trunnion page extends to DN1400 while the floating page stops at DN200. | DN15 to DN200 | DN50 to DN1400 |
| Pressure class The bases differ: the floating page quotes PN series and ASME classes side by side, the trunnion page quotes ASME classes only. | PN10 to PN160, Class 150 to Class 2500 | Class 150 to Class 1500 |
| Materials | ||
| Body materials Same meaning (available body grades), different lists: the trunnion page extends to duplex F51 and super duplex F53 for chloride duty; the floating page lists four conventional grades. | WCB, A105, CF8, CF8M | ASTM A105, A182 304/316/304L/316L, A182 F51, A182 F53 |
| Seat materials Both pages list soft and metal seat options; the compounds differ and are confirmed against the medium at RFQ. | EPDM, Metal, Viton, PTFE, NBR | PTFE, RTFE, Nylon, Metal to Metal |
| Connections & operation | ||
| End connections The floating page lists the connection set explicitly; the trunnion page instead lists flange and butt-weld standards (ANSI B16.5, MSS SP-44/ASME B16.47, ANSI B16.25) without a collected connection list. | RF, RTJ, BW | Flange standards collected (ANSI B16.5 (2"-24"), MSS SP-44 / ASME B16.47 (over 26"), butt-weld ends ANSI B16.25); connection pattern list not collected — confirm the end pattern at RFQ Conditional — confirm at RFQ |
| Operation The lists differ: the trunnion page adds lever and pneumatic actuation; the floating page starts at a bare handle. | Handle, Gear Operated, Electric Actuated | Lever, Gear Operated, Pneumatic Actuated, Electric Actuated |
| Standards & duty | ||
| Fire-safe design The trunnion page lists fire-safe execution to API 607 for hydrocarbon service; no fire-safe listing is collected for the floating execution. | Not established by the collected evidence — confirm at RFQ Unverified — confirm at RFQ | API 607 |
| Design standards Near-identical basis for both executions: ASME B16.34, BS5351, API 6D and API 608 appear on both pages. | ASME B16.34, BS5351, API 6D, API 608 | API 6D, API 608, BS5351, ASME B16.34 |
| Temperature range The floating page states an operating window; no temperature range is collected for the trunnion execution. | -46°C to 120°C | Not established by the collected evidence — confirm at RFQ Unverified — confirm at RFQ |
- Specified
- Differs — read the note
- Unverified — confirm at RFQ
- Conditional — confirm at RFQ
How to choose
Choose floating up to DN200 — the pressure does the seating
The floating execution is the compact forged-body choice for small and medium bores at high class: the benchmark page covers DN15 to DN200 in PN10–PN160 / Class 150–2500 with RF, RTJ and butt-weld ends, and the forged A105/A182 construction suits high-pressure, high-integrity service where a casting would be the weak point. Select by working pressure class first — the forged execution reaches Class 2500, above where cast floating bodies usually stop — then by seat material against line temperature and by end connection against the piping standard.
Choose trunnion for large bore, chloride duty or fire-safe service
The trunnion execution anchors the ball top and bottom, which is what lets it hold tight shutoff on large bore and high pressure lines: DN50 to DN1400 at Class 150–1500 on the benchmark page. Material selection runs from ASTM A105 through A182 304/316/L grades to duplex F51 and super duplex F53 for chloride duty, with metal-to-metal seats for high temperature or abrasive service and API 607 fire-safe execution for hydrocarbons. Flange dimensions follow ANSI B16.5 up to 24 inch and MSS SP-44 / ASME B16.47 above.
The overlap band DN50–DN200 is a real decision
Both pages cover DN50–DN200, and there the choice is about seating behaviour, not capability: floating keeps the simpler, cheaper internals while the trunnion adds the anchored ball, the wider material list and the fire-safe option. In that band, decide on the duty — clean isolation stays floating, hydrocarbon or chloride service moves to trunnion — and confirm seat compound and execution details at RFQ.
Frequently asked questions
When does a floating ball valve stop being the right choice?
At large bore or high torque duty. On a floating ball there is no bearing support between ball and stem — line pressure seats the ball against the downstream seat, and as the bore and pressure grow the torque needed to operate it grows with them. The collected selection guidance states the limit directly: at large bore or high torque duty the floating principle itself becomes the limit, and a trunnion-mounted execution should be specified instead of treating the two as interchangeable. The size bands make the crossover concrete: the floating benchmark page stops at DN200 while the trunnion page runs to DN1400.
Why does the trunnion page carry a fire-safe listing and the floating page not?
That is what the two collected pages state, not a judgement about the executions. The trunnion benchmark page lists fire-safe design to API 607, which is why it is recommended for hydrocarbon service; no fire-safe listing is collected on the floating page. If you need a fire-safe floating execution, raise it in the RFQ rather than assuming either way — the requirement is confirmed against the offered execution in the quotation.
Why do some cells say "Unverified — confirm at RFQ"?
This page only states figures the collected evidence supports, and it never mixes bases. Where a field is collected for one execution but not the other — end connections, fire-safe design, temperature range — the empty side is marked instead of filled from general knowledge. Attach your medium, temperature, size and end-connection standard to the RFQ; the missing figures are confirmed in the quotation.
Individual execution specification pages
Each execution compared above has its own page — full specification table, selection guidance and RFQ details.
Ordering & documentation
Documents
Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
Send the medium, temperature, pressure, size and connection for a quotation-ready inquiry. Lead time, MOQ and price are confirmed at quotation, together with the documents to be supplied with the order.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.
Knowledge: selection guides
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