Ultimate Guide to Valve Trim: API Trim Chart, Materials, Types & Selection (2025 Edition)

1. Introduction: What Is Valve Trim?

Valve trim refers to all internal parts of a valve that come into direct contact with the fluid and control the flow. These components determine the valve’s performance, flow characteristics, sealing, and resistance to corrosion or erosion.

1.1 Valve Trim Definition

In valve engineering, valve trim includes the following parts:

• Plug / Disc / Ball / Gate

• Seat or seat ring

• Stem

• Backseat

• Sleeve or guide bushings

• Gaskets and packing (sometimes included depending on standard)

Trim = All wetted, functional, and replaceable parts controlling flow.

1.2 Why Valve Trim Matters

Valve trim determines:

• Flow control accuracy

• Shutoff capability

• Chemical compatibility

• Resistance to erosion, corrosion, cavitation

• Safety performance

• Valve lifespan

Trim selection is critical for:

• Oil & gas

• Chemical & petrochemical

• Refining

• Power generation

• Water and wastewater

• Marine and offshore

2. What Components Are Included in Valve Trim?

(Full technical explanation)

2.1 Gate Valve Trim

Includes:

• Wedge / gate

• Seats

• Stem

• Backseat bushing

• Seat ring

2.2 Globe Valve Trim

• Disc (plug)

• Seat ring

• Stem

• Cage (control valve)

2.3 Ball Valve Trim

• Ball

• Seats (soft or metal)

• Stem

2.4 Control Valve Trim

The most complex:

• Plug

• Seat

• Stem

• Cage

• Guides

• Seals

• Characterization elements (equal %, linear)

Includes Cavitation-resistant trims:

• Multi-hole cage trim

• Multi-stage trim

• Anti-cavitation trim

• Noise-reduction trim

3. Valve Trim Material Overview

Valve trim uses different material classes:

3.1 Stainless Steels (Trim 8, Trim 5, etc.)

• 304

• 316

• 316 + HF

• Stellite hardfacing

3.2 Carbon Steels

• A105

• 410 SS faced

• HF coatings

3.3 Hardfacing Alloys

Used for severe service:

• Stellite 6

• Alloy 6

• Tungsten carbide

• Colmonoy

• Chromium carbide

3.4 Special Alloys

• Monel

• Inconel

• Hastelloy

• Duplex / Super Duplex

• Titanium

3.5 Soft Trim Materials (control valves)

• PTFE

• RPTFE

• EPDM

• Viton

• PEEK

• Delrin

4. API Valve Trim Chart (FULL)

✔ Covers API 600, 602, 603, 608
✔ Includes Trim Numbers 1–16
✔ Includes materials & applications
✔ High-value SEO section

# 5. Full API Valve Trim Chart (API 600, API 602, API 603, API 608)

The most complete API valve trim chart available online.

This chart lists all commonly used API valve trim numbers, materials, and recommended applications.

5.1 API Trim Chart (Master Table)

✔ Covers Trim Numbers 1–16

✔ Includes Material, Hardfacing, Seat Type, and Applications

✔ Ideal for SEO & Engineering Reference

API Valve Trim Chart (Full Table)

5.2 API Trim Quick Summary (Easy Reference)

Most Common API Trims

• Trim 1 → Basic service

• Trim 5 → Steam, high temp, erosion

• Trim 8 → Chemical service

• Trim 12 / 13 → Severe service, high erosion

• Trim 16 → Offshore & high chlorides

Corrosion-resistant Trims

• Trim 8 (316 SS)

• Trim 9 (Monel)

• Trim 14 (Hastelloy)

• Trim 15 (Titanium)

Hardfaced Trims

• Trim 5

• Trim 10

• Trim 12

• Trim 13

These are used when erosion or high temperatures are expected.

# 6. Trim 5 vs Trim 8 (Important Comparison Section)

Which one should you choose?

• High temperature, steam, erosion → Trim 5

• Chemical service, chlorides, acidic environments → Trim 8

# 7. API 600 / API 602 Trim Chart (Simplified)

API 600 (Gate / Globe / Check Valves)

Most used trims:

API 602 (Small Forged Steel Valves)

Common trims:

# 8. NACE Valve Trim Chart (MR0175 / ISO 15156)

NACE-Compliant Trims

Used for sour gas (H₂S) applications.

Most used NACE trim:
→ Trim 8 (316 SS) and Trim 9 (Monel)

# 9. Valve Trim Types (Full Classification)

This section covers the keyword cluster:

• valve trim types

• control valve trim

• valve trim material types

9.1 By Material

• Carbon steel trims

• Stainless steel trims

• Alloy trims

• Hardfaced trims

• Soft seat trims

• Elastomer trims

9.2 By Service Type

• Standard trim

• Corrosion-resistant trim

• Erosion-resistant trim

• High-temperature trim

• Cryogenic trim

• NACE sour gas trim

9.3 In Control Valves

• Cage-guided trim

• Multi-stage trim (anti-cavitation)

• Noise-reducing trim

• Quick-change trim

• Characterized trim (equal %, linear, modified linear)

10. Valve Trim Material Selection Guide (How to Choose the Right Trim)

Selecting the correct valve trim material determines whether a valve lasts 30 years or fails in 3 months. The wrong trim leads to leakage, galling, corrosion, erosion, or complete failure.

Below is a step-by-step material selection guide used by engineers.

Step 1 — Define the Fluid Type

Material compatibility is the first filter.

✔ Compatible With Most Fluids

• 304, 316 stainless steel

• Monel

• Hastelloy B/C

• Bronze

✔ For Corrosive / Chloride / Sour Service

• 316 SS

• 316+Hardfacing

• Duplex / Super Duplex

• Hastelloy C276

• Monel 400

• Inconel 625

✔ For Hydrocarbon / Steam

• 410 SS (hardened)

• 13Cr

• Stellite hardfacing

Step 2 — Identify Temperature Range

Step 3 — Consider Pressure & Velocity (Erosion Risk)

High velocity or flashing → erosion-resistant trim.

Best choices:

• Stellite 6

• Tungsten carbide

• 410 SS hardened

• Inconel / Monel

Avoid bronze or soft stainless steels in erosive media.

Step 4 — Check Need for Hardfacing / Anti-Galling

Galling often occurs in stainless-on-stainless trim.
Use:

• Stellite facing

• Nitrided surfaces

• Hardened 410 SS

Step 5 — Sour Service (H₂S) Requirements – NACE MR0175 Compatibility

✔ Monel
✔ Inconel
✔ Hastelloy
✔ Duplex / Super Duplex
✔ Stellite

✘ 410 SS (only limited use unless specially heat treated)
✘ 13Cr (risk of SSC)

For sour applications, always verify:

• Hardness limits

• SSC resistance

• Sulfide cracking compliance

11. Valve Trim Types (Based on Function)

A. Control Valve Trim Types

• Cage-guided trim – stable, low vibration

• Plug & seat trim – common for throttling

• Multi-hole / Anti-cavitation trim – eliminates noise and flashing

• Equal percentage / linear trim – flow characteristic options

B. On–Off Valve Trim Types

• Wedge gate trim

• Globe plug trim

• Ball valve seats & ball trims

• Butterfly valve discs

12. API Trim 1–17 Explained (Material Overview)

You have the full chart earlier—this section gives real-world use cases.

Trim 1 – 410 SS

Best for:

• Water

• Steam

• General hydrocarbons

• Moderate temp applications

Avoid:

• Chlorides (pitting)

• Sour service

Trim 5 – 410 SS + Stellite

Best for:

• High-temperature valves

• Steam service

• Anti-galling, high wear applications

Common in:

• Refinery isolation valves

• Power plants

• High-cycle globe valves

Trim 8 – 316 SS

Best for:

• Corrosive fluids

• Chemical plants

• Moderate chlorides

Avoid:

• High-cycle erosion

• Cavitation

Trim 10 – Monel 400

Best for:

• Brine

• Saltwater

• Sour gas

Excellent chloride resistance.

Trim 12 – 316 SS + Hardfacing

Best for:

• Corrosive + erosive service

• Offshore

• Chemical injection lines

Trim 13 – Alloy 20

Best for:

• Sulfuric acid

• Highly acidic service

• Severe corrosion environments

Trim 16 – Hastelloy C

Best for:

• Corrosive + high temp

• Chlorine, seawater

• Chemical reactors

Trim 17 – Stellite

Best for:

• Extreme erosion

• High temperature

• Severe throttling

• Cavitation control

Most durable trim material.

13. Valve Trim Number System (How to Read It)

The “trim number” defines:

• Stem material

• Plug/disc material

• Seat material

• Hardfacing type

• Facing material

This ensures standardization across manufacturers:

• API 600 (gate valves)

• API 602 (compact gates/globes)

• API 603 (corrosion-resistant valves)

Important: Trim number ≠ body material.
Trim only refers to internal wetted moving parts.

14. Control Valve Trim (Special Features)

Control valve trim includes:

• Seat ring

• Plug

• Stem

• Guide bushings

• Cage (optional)

• Anti-cavitation elements

Different control trim designs:

• Single-stage

• Multi-stage

• Multi-hole cage

• Low-noise trim

• Anti-flashing trim

15. Gate Valve Trim Chart (API 600 Focus)

Common gate valve trim selections:

16. Valve Body Material vs Valve Trim (Don’t Confuse Them)

Valve body material = main pressure boundary
Trim material = internal sealing & moving parts

Common combination examples:

17. FAQs

1. What is valve trim?

All internal wetted parts that control, shut off, or regulate flow.

2. Does body material determine trim?

No — trim is chosen based on fluid, temperature, and pressure.

3. Is Stellite the best trim?

Yes for:

• High temp

• Severe erosion

• High cycle service

But not needed for simple water or low-pressure service.

4. What is the difference between Trim 5 and Trim 8?

• Trim 5 = 410 SS + Stellite (strong, good for steam)

• Trim 8 = 316 SS (corrosion resistance)

5. What trim is best for seawater?

Monel (Trim 10)
or
Duplex + Stellite (Custom trims)