TECTULby IMR

Fluid conveyance · Stainless steel globe valves

TECHNICAL DATA SHEET

FT-TC-VAL-GLOBO-INOX-001

Issue date: August 4, 2026 · Rev. 001

Check the current version

Threaded globe valve in ASTM A351 CF8M stainless steel — 200 WOG confirmed by the manufacturer

TECTUL · Dispatch across Colombia · Exports to Central & South America

NPT threaded globe valve in ASTM A351 grade CF8M cast stainless steel — the cast equivalent of 316 — with an axial disc on a seat in the flow path, asbestos-free PTFE packing and tapered NPT threaded ends per ASME B1.20.1. Five published sizes from 1/2″ to 2″ (DN 15 to DN 50). It is the only reference in the threaded gate, globe and angle family whose manufacturer publishes the rating: 200 WOG. This sheet uses that figure as its backbone and develops its correct reading — 200 psi only when cold and non-shock, equivalent to Class 125 of the MSS SP-80 dual system, that is 125 psig of saturated steam at ≈178 °C — together with the CF8M-versus-bronze material criterion.

SKU VT-59216 (200 Psi stainless globe valve) · 1 reference, 5 published sizes from 1/2″ to 2″

1. Technical specifications

Materials by component

Composition and CF8M↔316 equivalence per ASTM A351/A351M. The exact stem grade, the handwheel material and the presence of a renewable seat ring are manufacturer data per figure: confirmed on quotation or in the PDF sheet attached to the product.

Standards and service framework

Size equivalence

Stainless globe reference in the TECTUL catalog

of the five published sizes only 3/4″ and 1″ are active; 1/2″, 1-1/2″ and 2″ are quoted to order with a lead time to be confirmed. The stainless globe line does not publish 1-1/4″. Face-to-face dimensions, height and weight by size are manufacturer data and are confirmed on quotation or in the attached factory PDF sheet.

2. What the "200 PSI" on this valve means exactly

This reference is the only one in the catalog's threaded gate, globe and angle family whose manufacturer publishes the rating. That number — 200 — even appears in the product's commercial name. Precisely for that reason it deserves a careful reading, because it is the figure most often misinterpreted at quotation time.

The 200 psi is a WOG, not a universal service pressure

The table that settles the reading

Why 200 WOG equals Class 125 (and what that implies on steam)

MSS SP-80 rates valves of this geometry with dual classes: each class carries a paired SWP (pressure on saturated steam) and WOG (cold pressure). The correspondence is fixed:

¹ Saturation temperature of steam at the stated SWP: it is a thermodynamic property of water, not of the valve. It is the same reference value ASME B16.3-2021 (Table 3-1, note 1) uses for the 186 °C limit of class 150 threaded fittings. Note the danger of the naive reading: Class 200 (200 psig of steam) is not the same thing as 200 WOG (which is Class 125 and only 125 psig of steam). The same number, 200, means different things in each column.

3. ASTM B62 bronze versus CF8M: when molybdenum justifies the premium

The catalog offers the same threaded globe geometry in two metals. The choice between them is not about pressure — both subfamilies move within the same class step — but about the chemistry of the fluid and of the environment. The element that explains it is molybdenum.

The three reasons that do NOT justify moving to CF8M

• "So it takes more pressure." No: the rating is set by the class of the figure, not by the metal. This stainless valve publishes 200 WOG (Class 125); a Class 300 bronze figure reaches 600 WOG, three times as much. If pressure is short, raise the class, do not change the metal.
• "So it takes more temperature." On these threaded valves the practical ceiling is set by the PTFE stem packing, which is the same in both subfamilies. CF8M metallurgically withstands much more, but the complete valve does not.
• "Because bronze dezincifies." B62 C83600 bronze contains only 4–6 % zinc, far below the threshold at which selective zinc loss becomes significant in copper-zinc alloys. That is why valve bronze, unlike some yellow brasses used in plumbing fittings, does not usually require a DZR grade.

4. Selection, throttling and installation

What makes a globe valve different

Unlike a gate valve, a globe valve forces the fluid to rise into a chamber, cross a horizontal orifice — the seat — and descend again; the disc moves parallel to the axis of that orifice. That geometry is what allows stable throttling: the flow area grows smoothly with stem travel and the disc stays guided, without chattering at intermediate positions. The cost is pressure drop: using the Crane TP-410 method, a fully open globe valve is represented by K = 340·fT against K = 8·fT for a gate valve of the same size, roughly 42 times more resistance. That is why globe valves are installed only where regulation is needed, and block points take gate valves.

The two limits of throttling

• Cavitation with liquids. When throttling, the local pressure at the vena contracta falls far below the downstream pressure. If it drops below the vapour pressure of the liquid at service temperature, bubbles form and implode as pressure recovers: it sounds like gravel and erodes seat and disc within weeks. CF8M resists erosion better than bronze, but is not immune. It is mitigated by staging the ΔP, raising the downstream pressure, or using a control valve designed for the service.
• Erosion with steam and gases. With wet steam or particle-laden gases, the high-velocity jet through a small opening erodes the seat by impact. If the working point always sits near closure, the valve is oversized: dropping a size is advisable.

Installation in stainless steel

• Thread and galling. NPT seals by tapered metal-to-metal interference (ASME B1.20.1). In stainless against stainless, PTFE tape or paste also performs a critical lubricating role: the austenitic threaded pair is prone to galling and a dry assembly can cold-weld the helices and ruin the joint. Apply the sealant on the male thread, never on the female, and tighten continuously without backing off.
• Flow direction. A globe valve does have one. The conventional arrangement takes the fluid under the disc, so that with the valve closed the bonnet and packing are depressurized. Respect the arrow cast on the body; if there is none, identify the seat arrangement before mounting. Reversing it subjects the packing to permanent pressure and can cause disc vibration at small openings.
• Tightening. Hold by the body with a wrench on the hexagonal end flats; never by the handwheel or the bonnet.
• Orientation. Preferably with the stem vertical and upward. On steam lines, avoid the stem pointing downward: condensate collects in the bonnet and punishes the packing.
• Operation. Open and close slowly, particularly on liquids, so as not to induce water hammer. When closing, tighten only enough to seal: forcing the handwheel onto a metal-to-metal seat deforms the disc.
• Chlorides and temperature. In chloride services above roughly 60 °C, chloride stress corrosion cracking of austenitic steels must be evaluated — a mechanism no pressure rating covers and which belongs to the project engineer.
• Maintenance. A drip at the stem is corrected by gradually tightening the gland; that is normal maintenance. A drip through the seat with the valve closed indicates disc or seat wear, not packing wear.

5. Frequently asked questions

What does "200 WOG" mean exactly on this valve?

WOG (Water-Oil-Gas) is the maximum allowable pressure with water, oil or gas cold and non-shock, between −29 °C and 38 °C. 200 WOG = 13.8 bar ≈ 140.6 m of water column. It is not an ASME B16.34 class — no "class 200 WOG" exists in that standard — but a manufacturer declaration under the MSS SP-80 framework. Above 38 °C the figure no longer applies.

Can I use it on 150 psi steam because it says 200 psi?

No. In the MSS SP-80 dual system, 200 WOG corresponds to Class 125, whose limit on saturated steam is 125 psig at ≈178 °C. Steam at 150 psig exceeds that SWP. This is the most frequent error with this reference: the 200 in the name is the cold figure, not the steam one. For 150 psig of steam you must step up to a Class 150 figure or higher.

Does the valve withstand 200 psi under water hammer?

The WOG is explicitly "non-shock". A rapid closure can generate an enormous surge: with the Joukowsky equation, arresting 2 m/s of water in steel pipe (celerity ≈1,200 m/s) produces ≈24 bar (≈348 psi) of peak, added to the line pressure. In systems with solenoid valves, pump start-stop or abrupt closures, the transient must be calculated and damped separately; it is not covered by the WOG.

What is the difference between "200 WOG" and "Class 200"?

They are different things even though they share the number. 200 WOG is the cold pressure of Class 125 (whose steam figure is 125 psig). MSS SP-80 Class 200 allows 200 psig of steam and 400 psi WOG cold — twice the cold pressure of this valve. Confusing them leads to installing a valve far below the service.

When is the stainless globe valve preferable to the bronze one?

When the criterion is chemical: chlorides (brackish water, brines, chlorinated water), process chemicals, ammoniacal compounds that attack copper, coastal environments with salt mist, or documentary sanitary and low-lead requirements. If the fluid is water, compressed air or non-corrosive oil and the installation is inland, the bronze globe valve is the lower-cost option.

Which sizes are available?

Five sizes are published — 1/2″, 3/4″, 1″, 1-1/2″ and 2″ (DN 15 to DN 50) — of which 3/4″ and 1″ are active; the rest are quoted to order with a lead time to be confirmed. The line does not publish 1-1/4″.

6. Application notes

7. Technical notice and limitation of liability