TECTULby IMR

Fluid conveyance · Stainless steel ball valves

TECHNICAL DATA SHEET

FT-TC-VAL-BOLA-INOX-001

Issue date: August 4, 2026 · Rev. 001

Check the current version

CF8M stainless steel ball valves — 1000 WOG (CWP) per MSS SP-110

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

Ball valves with body and ball investment-cast in ASTM A351 grade CF8M —the cast equivalent of AISI 316, with Cr 18–21 %, Ni 9–12 %, Mo 2–3 % and C ≤0.08 %— and a reinforced PTFE seat. The line's working rating is 1000 WOG/CWP (68.9 bar) at ≤38 °C per MSS SP-110: a manufacturer-certified cold pressure, not an ASME Class. This sheet covers the five stainless constructions in the TECTUL catalog —two-piece, four-bolt, six-bolt, high pressure and three-way— plus the sanitary version with ISO 2852 clamp ends, together with the in-line maintainability criterion, flow capacity (Cv 36 on 1″ full port) and diversion versus mixing on three-way bodies.

SKU VT-59181 (stainless two-piece ball valve) · 6 CF8M stainless steel references, 1/4″–4″ · sold by the unit

1. Technical specifications

Materials by component

CF8M chemical composition per ASTM A351

TECTUL catalog references in stainless steel

The high-pressure and sanitary clamp references are published in the catalog with no diameter list: their dimensional scope and rating are confirmed on quotation.

General specifications

2. 1000 WOG rating and flow capacity: CF8M and Cv

What 1000 WOG means on a stainless valve

The 1000 WOG figure is the line's Cold Working Pressure (CWP): the maximum allowable pressure with water, oil or non-flammable gas (Water-Oil-Gas), measured cold, between −29 °C and +38 °C (−20 °F to 100 °F). WOG and CWP are the same value. It is not an ASME B16.34 Class: a class is a full pressure-temperature table by material group, with a different value at each thermal step; WOG is a single number the manufacturer certifies cold. MSS SP-110 requires each valve to declare its "Pressure-Temperature Ratings" section, but publishes no mandatory derating table common to the whole standard — hence 1000 WOG is the line's working value, verified against market practice, and the full curve is requested from the manufacturer of the quoted reference.

Why stainless reaches 1000 while bronze stops at 600

The difference is not one of standard but of material: CF8M has appreciably higher strength and yield than cast copper alloys, so at equivalent wall thicknesses the austenitic body sustains a higher cold rating. Add to that investment casting, which produces uniform wall thickness and a smooth internal surface without the porosity typical of sand-cast bronze. The seat, however, is the same RPTFE in both families: that is why the thermal ceiling does not improve when moving to stainless, only the pressure ceiling.

CF8M composition and behavior

CF8M is the cast equivalent of AISI 316. Its distinguishing feature against CF8 (the 304 equivalent) is molybdenum 2–3 %, which raises resistance to pitting and crevice corrosion in the presence of chlorides: chlorinated process water, dilute brines, marine environments, food lines. Carbon ≤0.08 % keeps the material within the standard austenitic range; if the process involved prolonged exposure to the sensitization range (approx. 425–870 °C) —which does not happen in a ball valve with a PTFE seat, because the seat would fail long before— a low-carbon grade would be specified. In this family's normal service, the seat is always the limiting factor.

Flow capacity: the line's Cv

The manufacturer catalog for the two-piece stainless line publishes Cv 36 for the 1″ full-port size. Cv is the water flow rate, in gallons per minute (US gpm), passing through the fully open valve with a 1 psi pressure drop. Its metric equivalent is Kv, in m³/h with a 1 bar drop: Kv ≈ Cv / 1.156 = 31.1. The working relationship is:

ΔP = SG × (Q / Cv)², with ΔP in psi, Q in US gpm and SG the fluid's specific gravity (1.0 for water).

Cv 36 corresponds to the 1″ size of the reference line. The Cv of the remaining diameters and of the three-way and high-pressure constructions is confirmed on quotation: a three-way ball's Cv is appreciably lower than a two-way ball of the same size, because the fluid turns inside the ball.

Thermal limit: set by the seat, not by CF8M

The CF8M body retains its properties well above the temperature at which the seat stops sealing. What governs is the polymer:

Above these ranges PTFE loses its sealing elasticity (creep) long before the stainless body fails from pressure. Choosing stainless raises the pressure ceiling and corrosion resistance, not the temperature ceiling: for that you would have to change the seat (PEEK, metal-to-metal), which is already a different valve family.

3. Construction: 2, 4 and 6 bolts, three-way and clamp ends

2, 4 and 6 bolts: what changes in maintainability

The bolt count indicates how the cap joins the body, and that determines whether the valve can be repaired without dismantling the pipe.

Beyond a certain diameter the cap flange needs more clamping points to spread the gasket load evenly: that is why the catalog moves from four to six bolts exactly at 4″, the line's largest diameter. The trade-off of the bolted body is a wider and costlier assembly than the two-piece threaded one.

The three-way valve: diversion and mixing, not simple shutoff

The three-way reference (1/4″ to 1″) is not an on-off shutoff valve: it is a flow routing element. Everything depends on the geometry of the ball bore:

The L or T configuration and the handle's rest position must be specified on quotation: two three-way valves of the same diameter and material behave differently depending on the ball inside. A three-way ball's Cv is lower than a two-way ball of the same size, because the fluid turns inside the ball.

Sanitary clamp ends (ISO 2852)

The sanitary reference replaces NPT ends with clamp ends per ISO 2852:1993 (clamp couplings for the food industry): the same joint system used by the sanitary stainless tubing line. The advantage over threading is not pressure but hygiene and intervention time: the clamp opens and closes by hand, leaves no thread where product can accumulate, and lets the valve be removed for cleaning without tools. The dimensions, tolerances and clamp/gasket system of that end live in data sheet FT-TC-TUB-INOXSAN-001 (sanitary stainless tubing) — this sheet does not repeat them: here the clamp reference enters as one more construction of the CF8M family, with its usual body and seat.

The high-pressure reference

The stainless high-pressure ball valve is a reinforced-wall body declaring a rating above the line's 1000 WOG. The catalog currently publishes it with no diameter list, so its exact rating, dimensional scope and construction (two or three piece) are confirmed on quotation with the real supplier. Do not specify it assuming the two-piece line's 1000 WOG: the correct number is whatever its manufacturer declares.

Blowout-proof stem and installation

The stem is fitted from inside the body, with a shoulder that bears against the body before reaching the packing: even if the packing fails or the gland nut loosens, internal pressure cannot eject it outward. When threading NPT, use PTFE tape or a compatible sealant and always hold the valve by the hex of the end being threaded, never by the handle — torque applied to the handle transmits to the stem and can misalign the ball.

4. Frequently asked questions

Is CF8M the same as 316 stainless steel?

It is its cast equivalent. AISI 316 (UNS S31600) is the designation for wrought or rolled material; CF8M of ASTM A351 is the casting specification with the same composition family: Cr 18–21 %, Ni 9–12 %, Mo 2–3 % and C ≤0.08 %. It is not a lower grade or a substitute: it is how that steel reaches a valve body, obtained by investment casting rather than bar machining.

How much pressure does a 1″ stainless ball valve withstand?

The line's working value is 1000 WOG (CWP): 1000 psi, 68.9 bar, with water, oil or non-flammable gas, cold (up to 38 °C). That figure applies equally to the two-piece and four-bolt line sizes. Above 38 °C you must come down the pressure-temperature curve of the quoted reference's manufacturer; MSS SP-110 publishes no common derating table.

When is the four-bolt version preferable to the two-piece?

When the valve sits at a point in the installation where removing it means stopping the line or cutting pipe. The bolted body opens in place to change seat and ball without touching the pipe; the two-piece threaded body is cheaper but forces dismantling. On a line with unions nearby, the two-piece usually suffices; on a welded or embedded assembly, the four-bolt pays for itself on the first intervention.

What is the difference between an L-port and a T-port three-way ball?

The L ball has a right-angle channel and connects two of the three ports at a time: it is for diverting flow to one outlet or the other. The T ball has a T-shaped channel and can connect all three ports at once: it is for mixing two streams or splitting one into two branches. Which one is needed must be stated on quotation, because from the outside the two valves look identical.

Does the sanitary clamp valve withstand the same pressure as the threaded one?

The body is the same CF8M, but the limiting factor stops being the body and becomes the joint system: an ISO 2852 clamp end with its clamp and gasket has its own rating, generally far below the 1000 WOG of the threaded body. Do not transfer the threaded line's number to the sanitary one: the allowable pressure of that reference is confirmed on quotation, along with the rating of the chosen clamp and gasket.

Is a CF8M stainless ball valve suitable for seawater?

CF8M's molybdenum greatly improves chloride pitting resistance over CF8, which is why it is the grade specified for chlorinated water, dilute brine and marine environments. For continuously circulating seawater, however, cast 316 is at the edge of its range and selection depends on temperature, fluid velocity and stagnation time: that analysis belongs to the line designer, and may end in a higher grade (duplex or superaustenitic) outside the scope of this sheet.

5. Application notes

6. Technical notice and limitation of liability