قطعات داخلی قابل جابجایی و قابل تعویض شیر که در تماس با محیط جریان قرار می گیرند، در مجموع به عنوان تریم نامیده می شوند. این قسمت ها شامل سیت، دیسک، گلند، اپیسر، گاید، بوشینگ و اسپرینگ است. بدنه شیر، درپوش، پکینگ و قطعات دیگر که در تماس با جریان سیال قرار می گیرند، تریم محسوب نمی شوند.
عملکرد تریم شیر توسط رابط دیسک و سیت و ارتباط موقعیت دیسک با سیت تعیین می شود. به دلیل نوع طراحی تریم، حرکات اصلی و کنترل جریان امکان پذیر می باشد. در طراحی های چرخشی، دیسک از نزدیک سیت عبور می کند تا تغییری در باز شدن جریان ایجاد کند. در طرح های حرکت خطی، دیسک به طور عمودی از سیت دور می شود تا یک حفره حلقوی ظاهر شود.
به دلیل ویژگی های مختلفی که برای مقاومت در برابر نیروها و شرایط مختلف مورد نیاز است، می توان از قطعات گوناگونی از تریم شیر استفاده کرد. بوشینگ ها و پکینگ گلندها همان نیروها و شرایطی را که دیسک و سیت تجربه می کنند، ندارند.
نوع سیال، ترکیب شیمیایی، فشار، دما، سرعت جریان سیال و ویسکوزیته برخی از ملاحظات مهم در انتخاب مواد مناسب جهت طراحی و ساخت تریم هستند. مواد استفاده شده می تواند از مواد استفاده شده در ساخت بدنه یا دیافراگم متفاوت باشد.
API با اختصاص یک عدد منحصر به فرد به هر مجموعه ای از مواد استفاده شده در تریم شیر، آن را استاندارد سازی کرده است:
API TRIM NO: 1
Nominal Trim
410
Trim code
F6
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6 (13Cr) (200 HBN)
Seat surface
410 (13Cr)(250 HBN min)
Trim Material Grade
13Cr-0.75Ni-1Mn
Service
For oil and oil vapors and general services with heat treated seats and wedges. General very low erosive or non-corrosive service between -100°C and 320°C. This stainless steel material lends itself readily to hardening by heat treatment and is excellent for contacting parts such as stems, gates, and discs. Steam, gas and general service to 370°C. Oil and Oil vapor 480°C
API TRIM NO: 2
Nominal Trim
304
Trim code
304
Stem and other trim parts
304
Disc/wedge
304 (18Cr-8Ni)
Seat surface
304 (18Cr-8Ni)
Trim Material Grade
19Cr-9.5Ni-2Mn-0.08C
Service
For moderate pressure in corrosive, low erosive service between -265°C and 450°C
API TRIM NO: 3
Nominal Trim
310
Trim code
310
Stem and other trim parts
(25Cr-20Ni)
Disc/wedge
310 (25Cr-20Ni)
Seat surface
310 (25Cr-20Ni)
Trim Material Grade
25Cr-20.5Ni-2Mn
Service
For moderate pressure in corrosive or non corrosive service between -265°C and 450°C
API TRIM NO: 4
Nominal Trim
410 - Hard
Trim code
F6H
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6 (13Cr) (200-275 HBN)
Seat surface
F6 (13Cr) (275 HBN min)
Trim Material Grade
13Cr-0.75Ni-1Mn
Service
Seats 275 BHN min. As trim 1 but for medium pressure and more corrosive service
API TRIM NO: 5
Nominal Trim
410 - Full Hard faced
Trim code
F6HF
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6+St Gr6 (CoCr Alloy) (350 HBN min)
Seat surface
410+St Gr6 (CoCr Alloy) (350 HBN min)
Trim Material Grade
13Cr-0.5Ni-1Mn/Co-Cr-A
Service
High pressure slightly erosive and corrosive service between -265°C and 650°C and higher pressure. Premium trim service to 650°C. Excellent for high pressure water and steam service
API TRIM NO: 5A
Nominal Trim
410 - Full Hard faced
Trim code
F6HF
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6+Hardf. NiCr Alloy (350 HBN min)
Seat surface
F6+Hardf. NiCr Alloy (350 HBN min)
Trim Material Grade
13Cr-0.5Ni-1Mn/Co-Cr-A
Service
As trim 5 where Co is not allowed
API TRIM NO: 6
Nominal Trim
410 and Ni-Cu
Trim code
F6HFS
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
Monel 400® (NiCu Alloy) (250 HBN min)
Seat surface
Monel 400® (NiCu Alloy) (175 HBN min)
Trim Material Grade
13Cr-0.5Ni-1Mn/Ni-Cu
Service
As trim 1 and more corrosive service
API TRIM NO: 7
Nominal Trim
410 - Very Hard
Trim code
F6HF+
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6 (13Cr) (250 HBN min)
Seat surface
F6 (13Cr) (750 HB)
Trim Material Grade
13Cr-0.5Ni-1Mo/13Cr-0.5Ni-Mo
Service
Seats 750 BHN min. As trim 1 but for higher pressure and more corrosive/erosive service
API TRIM NO: 8
Nominal Trim
410 - Hard faced
Trim code
F6HFS
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
410 (13Cr) (250 HBN min)
Seat surface
410+St Gr6 (CoCr Alloy) (350 HBN min)
Trim Material Grade
13Cr-0.75Ni-1Mn/1/2Co-Cr-A
Service
Universal trim for general service requiring long service life up to 593°C. As trim 5 for moderate pressure and more corrosive service. Steam, gas and general service to 540°C. Standard trim for gate valves
API TRIM NO: 8A
Nominal Trim
410 - Hard faced
Trim code
F6HFS
Stem and other trim parts
410 (13Cr) (200-275 HBN)
Disc/wedge
F6 (13Cr) (250 HBN min)
Seat surface
410+Hardf. NiCr Alloy (350 HBN min)
Trim Material Grade
13Cr-0.75Ni-1Mn/1/2Co-Cr-A
Service
As trim 5A for moderate pressure and more corrosive service
API TRIM NO: 9
Nominal Trim
Monel®
Trim code
Monel®
Stem and other trim parts
Monel® (NiCu Alloy)
Disc/wedge
Monel 400® (NiCu Alloy)
Seat surface
Monel 400® (NiCu Alloy)
Trim Material Grade
70Ni-30Cu
Service
For corrosive service to 450°C such as acids, alkalies, salt solutions, etc. Very corrosive fluids.
Erosive-corrosive service between -240°C and 480°C. Resistant to sea water, acids, alkalies. Has excellent corrosion resistance in chlorine and alkylation service
API TRIM NO: 10
Nominal Trim
316
Trim code
316
Stem and other trim parts
316 (18Cr-Ni-Mo)
Disc/wedge
316 (18Cr-Ni-Mo)
Seat surface
316 (18Cr-Ni-Mo)
Trim Material Grade
18Cr-12Ni-2.5Mo-2Mn
Service
For superior resistance to corrosion for liquids and gases which are corrosive to 410 stainless steel up to 455°C. As trim 2 but a higher level of corrosive service. Provides excellent resistance to corrosive media at high temperatures and toughness for service at low temperatures. Low temperature service standard for 316SS valves
API TRIM NO: 11
Nominal Trim
Monel - Hard faced
Trim code
MonelHFS
Stem and other trim parts
Monel® (NiCu Alloy)
Disc/wedge
Monel® (NiCu Alloy)
Seat surface
Monel 400®+St Gr6 (350 HBN min)
Trim Material Grade
70Ni-30Cu/1/2Co-Cr-A
Service
As trim 9 but for medium pressure and more corrosive service
API TRIM NO: 11A
Nominal Trim
Monel - Hard faced
Trim code
MonelHFS
Stem and other trim parts
Monel® (NiCu Alloy)
Disc/wedge
Monel® (NiCu Alloy)
Seat surface
Monel 400T+HF NiCr Alloy (350 HBN min)
Trim Material Grade
70Ni-30Cu/1/2Co-Cr-A
Service
As trim 9 but for medium pressure and more corrosive service
API TRIM NO: 12
Nominal Trim
316 - Hard faced
Trim code
316HFS
Stem and other trim parts
316 (Cr-Ni-Mo)
Disc/wedge
316 (18Cr-8Ni-Mo)
Seat surface
316+St Gr6 (350 HBN min)
Trim Material Grade
18Cr-12Ni-2.5Mo-2Mn1/2Co-Cr-A
Service
As trim 10 but for medium pressure and more corrosive service
API TRIM NO: 12A
Nominal Trim
316 - Hard faced
Trim code
316HFS
Stem and other trim parts
316 (Cr-Ni-Mo)
Disc/wedge
316 (18Cr-8Ni-Mo)
Seat surface
316 Hardf. NiCr Alloy (350 HBN min)
Trim Material Grade
18Cr-12Ni-2.5Mo-2Mn1/2Co-Cr-A
Service
As trim 10 but for medium pressure and more corrosive service
API TRIM NO: 13
Nominal Trim
Alloy 20
Trim code
Alloy 20
Stem and other trim parts
Alloy 20 (19Cr-29Ni)
Disc/wedge
Alloy 20 (19Cr-29Ni)
Seat surface
Alloy 20 (19Cr-29Ni)
Trim Material Grade
29Ni-19Cr-2.5Mo-0.07C
Service
Very corrosive service. For moderate pressure between -45°C and 320°C
API TRIM NO: 14
Nominal Trim
Alloy 20 - Hard faced
Trim code
Alloy 20HFS
Stem and other trim parts
Alloy 20 (19Cr-29Ni)
Disc/wedge
Alloy 20 (19Cr-29Ni)
Seat surface
Alloy 20 St Gr6 (350 HBN min)
Trim Material Grade
29Ni-19Cr-2.5Mo-0.07C/1/2Co-Cr-A
Service
As trim 13 but for medium pressure and more corrosive service
API TRIM NO: 14A
Nominal Trim
Alloy 20 - Hard faced
Trim code
Alloy 20HFS
Stem and other trim parts
Alloy 20 (19Cr-29Ni)
Disc/wedge
Alloy 20 (19Cr-29Ni)
Seat surface
Alloy 20 Hardf. NiCr Alloy (350 HBN min)
Trim Material Grade
29Ni-19Cr-2.5Mo-0.07C/1/2Co-Cr-A
Service
As trim 13 but for medium pressure and more corrosive service
API TRIM NO: 15
Nominal Trim
304 - Full Hard faced
Trim code
304HS
Stem and other trim parts
304 (18Cr-8Ni-Mo)
Disc/wedge
304St Gr6
Seat surface
304+St Gr6 (350 HBN min)
Trim Material Grade
19Cr-9.5Ni-2Mn-0.08C/1/2Co-Cr-A
Service
As trim 2 but more erosive service and higher pressure
API TRIM NO: 16
Nominal Trim
316 - Full Hard faced
Trim code
316HF
Stem and other trim parts
316 HF (18Cr-8Ni-Mo)
Disc/wedge
316+St Gr6 (320 HBN min)
Seat surface
316+St Gr6 (350 HBN min)
Trim Material Grade
18Cr-12Ni-2.5Mo-2Mn/Co-Cr-Mo
Service
As trim 10 but more erosive service and higher pressure
API TRIM NO: 17
Nominal Trim
347 - Full Hard faced
Trim code
347HF
Stem and other trim parts
347 HF (18Cr-10Ni-Cb)
Disc/wedge
347+St Gr6 (350 HBN min)
Seat surface
347+St Gr6 (350 HBN min)
Trim Material Grade
18Cr-10Ni-Cb/Co-Cr-A
Service
As trim 13 but more corrosive service and higher pressure. Combines good corrosion resistance with high temperature resistance up to 800°C
API TRIM NO: 18
Nominal Trim
Alloy 20 - Full Hardfaced
Trim code
Alloy 20 HF
Stem and other trim parts
Alloy 20 (19Cr-29Ni)
Disc/wedge
Alloy 20+St Gr6 (350 HBN min)
Seat surface
Alloy 20+St Gr6 (350 HBN min)
Trim Material Grade
19 Cr-29Ni/Co-Cr-A
Service
As trim 13 but more corrosive service and higher pressure. Water, gas or low pressure steam to 230°C
API TRIM NO: Special
Nominal Trim
Bronze
Trim code
Bronze
Stem and other trim parts
410 (CR13)
Disc/wedge
Bronze
Seat surface
Bronze
Service
Water, oil, gas, or low pressure steam to 232°C
API TRIM NO: Special
Nominal Trim
Alloy 625
Trim code
Alloy 625
Stem and other trim parts
Alloy 625
Disc/wedge
Alloy 625
Seat surface
Alloy 625
API TRIM NO: NACE
Specially treated 316 or 410 trim combined with B7M bolts and 2HM nuts to meet NACE MR-01-75 requirements
API TRIM NO: Full Stellite
Full Hardfaced trim, suitable for abrasive and severe services up to 1200°F (650°C)
Note: Data provided about API Trim numbers is for informational purposes only. Always consult current API publications to verify information and trim date